fix(deps): bump supported Go versions to 1.22.6 and 1.21.13

[github-actions[bot]]

It's time to update Relay's supported Go versions, due to a recent upstream Go release.

The Go major release cadence is ~every 6 months; the two most recent major versions are supported. Note that between major releases, the Go team often ships multiple minor versions.

	Current repo configuration	Desired repo configuration
Latest	1.22.5	1.22.6
Penultimate	1.21.12	1.21.13

This PR's change was generated by running:

./scripts/update-go-release-version.sh 1.22.6 1.21.13

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