Bump codecov/codecov-action from 4 to 5 #1638

Job	Run time
Validate external types appearing in public API	1m 32s
build (macOS-latest, stable)	3m 57s
build-windows	14m 50s
Build rustls-cert-gen as a standalone package	30s
build (ubuntu-latest, stable)	6m 6s
build (ubuntu-latest, beta)	6m 5s
Measure coverage	5m 51s
Format & clippy	5m 24s
build (ubuntu-latest, nightly)	5m 40s
build (ubuntu-latest, stable 7 months ago)	6m 3s
Check semver compatibility	54s
Documentation (stable)	58s
Documentation (nightly)	1m 5s
	58m 55s

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