45.0.2 release

Backport mypy fixes for release (#12930)

* mypy cleanups for Python 3.8 (#12928)

should unblock #12927

* fix typing on release.py with older python (#12929)

* fix(x509): use backward compatible syntax for types (#12927)

* fix(x509): use backward compatible syntax for types

* add Python 3.8 flake to ci

* Backport mypy fixes for release

* sigh

* sigh

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Co-authored-by: Ivan Shcheklein <shcheklein@gmail.com>

• .github/workflows/ci.yml[diff]
• CHANGELOG.rst[diff]
• noxfile.py[diff]
• pyproject.toml[diff]
• release.py[diff]
• src/cryptography/__about__.py[diff]
• src/cryptography/hazmat/bindings/_rust/x509.pyi[diff]
• src/cryptography/hazmat/primitives/serialization/ssh.py[diff]
• tests/x509/verification/test_limbo.py[diff]
• vectors/cryptography_vectors/__about__.py[diff]
• vectors/pyproject.toml[diff]