How to rollback laravel version to the old one?

Question

Composer

I have this error when installing any packages
Installation failed, reverting ./composer.json to its original content.
rummaged through everything in the search - nothing helped

for version 6, everything is installed okay,
the current version of Laravel Framework 7.26.1

when I do a downgrade (I change the version in the composer and do an update either in manual mode composer require laravel/framework=6.0.3) again this error

Problem 1
- illuminate/support v5.7.9 requires nesbot/carbon ^1.26.3 -> satisfiable by nesbot/carbon[1.26.3,
1.26.4, 1.26.5, 1.26.6, 1.27.0, 1.28.0, 1.29 .0, 1.29.1, 1.29.2, 1.30.0, 1.31.0, 1.31.1, 1.32.0, 1.33.0, 1.3
4.0, 1.34.1, 1.34.2, 1.34.3, 1.34.4, 1.35.0, 1.35.1, 1.36.0, 1.36.1, 1.36.2, 1.37.0, 1.37.1, 1.38.0, 1.38.1,
1.38.2, 1.38.3, 1.38.4, 1.39. 0, 1.39.1] but these conflict with your requirements or minimum-stabilit
y.
- illuminate/support v5.7.8 requires nesbot/carbon ^1.26.3 -> satisfiable by nesbot/carbon[1.26.3, 1.
26.4, 1.26.5, 1.26.6, 1.27.0, 1.28.0, 1.29.0, 1.29.1, 1.29.2, 1.30.0, 1.31.0, 1.31.1, 1.32.0, 1.33.0, 1.3
4.0, 1.34.1, 1.34.2, 1.34.3, 1.34.4, 1.35.0, 1.35.1, 1.36.0, 1.36.1, 1.36.2, 1.37.0, 1.37.1, 1.38.0 ,
1.38.1, 1.38.2, 1.38.3, 1.38.4, 1.39.0, 1.39.1] but these conflict with your requirements or minimum-stabilit
y.
- illuminate/support v5.7.7 requires nesbot/carbon ^1.26.3 -> satisfiable by nesbot/carbon[1.26.3,
1.26.4, 1.26.5, 1.26.6, 1.27.0, 1.28.0, 1.29.0 1.29.1 1.29.2 1.30.0 1.31.0 1.31.1 1.32.0 1.33.0
1.34.0 0, 1.35.1, 1.36.0, 1.36.1, 1.36.2, 1.37.0, 1.37.1, 1.38.0, 1.38
.1, 1.38.2, 1.38.3, 1.38.4, 1.39.0, 1.39.1] but these conflict with your requirements or minimum-stabilit
y.
.....
- don't install illuminate/session 5.8.x-dev|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.0|don't install laravel/framework v6. 0.3
- don't install illuminate/session v5.8.11|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.12|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.14|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.15|don'
- don't install illuminate/session v5.8.17|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.18|don't install laravel/framework v6.0.3
- don't install illuminate /session v5.8.19|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.2|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.20| don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.22|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.24|don't install laravel/ framework v6.0.3
- don't install illuminate/session v5.8.27|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.28|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.29|don't install laravel/framework v6.0.3
- don't install illuminate /session v5.8.3|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.30|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.31| don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.32|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.33|don't install laravel/ framework v6.0.3
- don't install illuminate/session v5.8.34|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.35|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.36|don't install laravel/framework v6.0.3
- don't install illuminate /session v5.8.4|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.8|don't install laravel/framework v6.0.3
- don't install illuminate/session v5.8.9| don't install laravel/framework v6.0.3
- don't install illuminate/view 5.8.x-dev|don't install laravel/framework v6.0.3
- don't install illuminate/view v5.8.0|don't install laravel/framework v6.0.3

and then such a list is 20 times more.

{
    "name": "laravel/laravel",
    "type": "project",
    "description": "The Laravel Framework.",
    "keywords": [
        "framework",
        "laravel"
    ],
    "license": "MIT",
    "require": {
        "php": "^7.2.5",
        "fideloper/proxy": "^4.2",
        "fruitcake/laravel-cors": "^2.0",
        "guzzlehttp/guzzle": "^6.3",
        "intervention/image": "^2.5",
        "laravel/framework": "6.0.3",
        "laravel/tinker": "^2.0",
        "laravel/ui": "^2.2",
        "laravelcollective/html": "~5.0",
        "nesbot/carbon": "^2.39"
    },
    "require-dev": {
        "facade/ignition": "^2.0",
        "fzaninotto/faker": "^1.9.1",
        "mockery/mockery": "^1.3.1",
        "nunomaduro/collision": "^4.1",
        "phpunit/phpunit": "^8.5"
    },
    "config": {
        "optimize-autoloader": true,
        "preferred-install": "dist",
        "sort-packages": true
    },
    "extra": {
        "laravel": {
            "dont-discover": []
        }
    },
    "autoload": {
        "psr-4": {
            "App\\": "app/"
        },
        "classmap": [
            "database/seeds",
            "database/factories"
        ]
    },
    "autoload-dev": {
        "psr-4": {
            "Tests\\": "tests/"
        }
    },
    "minimum-stability": "dev",
    "prefer-stable": true,
    "scripts": {
        "post-autoload-dump": [
            "Illuminate\\Foundation\\ComposerScripts::postAutoloadDump",
            "@php artisan package:discover --ansi"
        ],
        "post-root-package-install": [
            "@php -r \"file_exists('.env') || copy('.env.example', '.env');\""
        ],
        "post-create-project-cmd": [
            "@php artisan key:generate --ansi"
        ]
    }
}