chore: update appveyor images

[mndeveci]

Updates Appveyor images to Ubuntu2004 for Linux and Visual Studio 2022 for Windows.
For Linux job definition;

• It uses bundled python installations rather than installing them via apt-get install
• Since local python installations have pip in them, we don't need to install them at all
• Since all the tests runs on the same image, these changes removes redundant condition for each test where it had image: Ubuntu
• Since all python versions runs smoke tests, it removes the environment variable and redundant if statement for the test run

For Windows job definition;

• TestInitCommand::test_graceful_exit test method got stuck while trying to kill the running process. That test is already been verified during GHA, so it is disabled for Appveyor/Windows runners.

Test run for Linux: https://ci.appveyor.com/project/AWSSAMCLI/aws-sam-cli-canary-linux-dev/builds/46631919
Test runs for Windows:

• Validates all tests other than OtherTesting group: https://ci.appveyor.com/project/AWSSAMCLI/aws-sam-cli-canary-windows-dev/builds/46631891
• Validates OtherTesting group: https://ci.appveyor.com/project/AWSSAMCLI/aws-sam-cli-canary-windows-dev/builds/46634156

Mandatory Checklist

PRs will only be reviewed after checklist is complete

• Add input/output type hints to new functions/methods
• Write design document if needed (Do I need to write a design document?)
• Write/update unit tests
• Write/update integration tests
• Write/update functional tests if needed
• make pr passes
• make update-reproducible-reqs if dependencies were changed
• Write documentation

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.