Update Go to 1.23.3

• Update CI image.
• Update golangci-lint (1.51 is not compatible with Go 1.23).
• Set default toolchain.

Part of a series:

• 👉 Update Go to 1.23.3 (!17 - merged)
• Update Go from 1.22.7 to 1.23.3 (gitlab-org/ci-cd/runner-tools/runner-linters!19 - merged)
• Bump Go compiler version to 1.23.2 (gitlab-org/gitlab-runner!5153 - merged)

Closes Bump golang to 1.23.3 (gitlab-org/gitlab-runner#38274 - closed)