test: move language scanner tests to longtests

[terriko]

In #4321 I've noted that our slowest tests are all instances of test_language_package.

While we figure out the best way to improve performance for those, I do think it would be good right now to accept that those are long tests and move them accordingly so they only run if long tests are enabled. This should be doable by a beginner but it may take some reading to understand how pytest parameterization and skipping work.

Step by step instructions:

• open up test/test_language_scanner.py and look at the function test_language_package
• This is a parameterized set of tests, so you can't just use pytest.skipif directly. Take a look at how I skipped tests in https://github.com/intel/cve-bin-tool/pull/4319/files (it's at the bottom of that diff, the changes in test_scanner.py)
• figure out how to change the parameters in test_language_package to achieve the same effect and do it!
• don't forget to run black test/test_language_scanner.py to make sure you're style compliant. It'll also let you know if there's a syntax error
• double-check your changes by trying to run pytest -k test_language_package on your local machine. If you get a bunch of sss notes showing skipped tests, you did it! (If you get a bunch of ... and the tests run, then try again)

[terriko]

Since I've flagged this as a good first issue, here's the standard tips:

Short tips for new contributors:

• cve-bin-tool's contributor docs
• If you've contributed to open source but not this project, you might just want our checklist for a great pull request
• cve-bin-tool uses https://www.conventionalcommits.org/ style for commit messages, and we have a test that checks the title of your pull request (PR). A good potential title for this one is in the title of this issue.
• You can make an issue auto close by including a comment "fixes #ISSUENUMBER" in your PR comments where ISSUENUMBER is the actual number of the issue. This "links" the issue to the pull request.

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