git: update dulwich to 0.20.22

[pmrowla]

• ❗ I have followed the Contributing to DVC checklist.

• 📖 If this PR requires documentation updates, I have created a separate PR (or issue, at least) in dvc.org and linked it here.

Thank you for the contribution - we'll try to review it as soon as possible. 🙏

• Related to dvc: consider switching from GitPython #2215
• Will close exp:Error "cannot stash changes - there is nothing to stash" on windows #5684
• Will close exp: running experiments is very slow #5638

[pmrowla]

dulwich now reads the system-wide default config, which means it will read core.autocrlf=true for typical windows Git environments. This should be disabled in CI, as DVC does not read Git configs, and will not do any autocrlf normalization when importing from Git.

Several of our tests git-commit files with CRLF's (usually via Windows echo which behaves differently than unix echo). If autocrlf=true, the original workspace file will have\r\n line endings, but the git-committed (and git-index) version will have nomalized \n line endings.

If we dvc import or dvc get that git committed file, DVC will read/download the git-committed version containing \n endings (even on Windows). This will break tests on Windows which do a direct comparison between the "original" workspace file and the imported one (since the line endings will not match).

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These tests passed with dulwich<0.20.22 because dulwich was always ignoring the system git config (meaning we always tested in CI with autocrlf disabled).

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It looks like the tests passed when we only used gitpython because the gitpython index.add function we used for scm.add may have been adding files directly into the git index without doing any CRLF normalization (meaning we were always ignoring the user's autocrlf setting entirely w/gitpython whether or not we were in the CI environment).