chore: update pre-commit and fix linter errors

[terriko]

• related: chore: update pre-commit config #3194

We have an automated script that updates the versions of linters and tools we use in pre-commit and if we upgrade flake8 to 6.1.0 it gives us a bunch of errors:

cve_bin_tool/cvedb.py:642:12: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
test/test_checkers.py:[32](https://github.com/intel/cve-bin-tool/actions/runs/5753663775/job/15597350652?pr=3194#step:7:33):16: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
test/test_checkers.py:33:16: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
test/test_checkers.py:34:16: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
test/test_checkers.py:35:16: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
test/test_checkers.py:36:16: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`

These should be pretty simple mechanical things to fix but it's been a few weeks and I haven't gotten around to it, so I'm opening this up as a beginner-friendly bug for someone to work on.

You need to:

• Re-use the changes from chore: update pre-commit config #3194 to update .pre-commit-config.yaml and dev-requirements.txt. The important one to change is flake8 but you might as well update them all.
• resolve any flake8 errors found when the new version is run (If you're not sure how to use pre-commit to run these, there's instructions here: https://github.com/intel/cve-bin-tool/blob/main/CONTRIBUTING.md#running-linters

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.

Claiming issues:

• You do not need to have an issue assigned to you before you work on it. To "claim" an issue either make a linked pull request or comment on the issue saying you'll be working on it.
• If someone else has already commented or opened a pull request, assume it is claimed and find another issue to work on.
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