Update Rust to 1.75.0

[arpad-m]

Release notes.

[github-actions]

2238 tests run: 2152 passed, 0 failed, 86 skipped (full report)

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Flaky tests (1)

Postgres 16

• test_crafted_wal_end[last_wal_record_crossing_segment]: debug

Code coverage (full report)

• functions: 54.8% (10056 of 18366 functions)
• lines: 81.6% (57643 of 70684 lines)

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_{The comment gets automatically updated with the latest test results
0434ad2 at 2024-01-08T05:20:37.370Z :recycle:}

[arpad-m]

Tag workflow as per CONTRIBUTING.md and per #6222 (comment) : https://github.com/neondatabase/neon/actions/runs/7446926961

[arpad-m]

Note for next upgrade: add the run-extra-build-macos label to it, like in #6294, to ensure there is no macOS regression. Add that label during filing of the PR to ensure the CI picks it up when it decides whether to build for macOS or not.