Update Go-based projects to Go 1.21 series

[atc0005]

Overview

Update Go-based projects from previous oldstable version (1.20) to latest oldstable version (1.21).

• update Dependabot configuration for Dockerfile to ignore Go releases outside of the Go 1.21 release series
• update "Canary" Dockerfile to reflect one release back from latest release in Go 1.21 series
  • confirm that Dependabot configuration changes are working as intended

NOTE: We intentionally do not update the Go module version; bumping the Go module version would indicate that this project requires a newer Go version for functionality provided by that version and that is not yet the case.

TODO

• [x] atc0005/bridge
• [x] atc0005/check-cert
• [x] atc0005/check-illiad
• [x] atc0005/check-mail
• [x] atc0005/check-ntpt
• [x] atc0005/check-path
• [x] atc0005/check-process
• [x] atc0005/check-restart
• [x] atc0005/check-rsat
• [x] atc0005/check-ssh
• [x] atc0005/check-statuspage
• [x] atc0005/check-vmware
• [x] atc0005/check-whois
• [x] atc0005/dnsc
• [x] atc0005/elbow
• [x] atc0005/go-ci
• [x] atc0005/go-lockss
• [x] atc0005/go-nagios
• [x] atc0005/go-teams-notify
• [x] atc0005/go-template
• [x] atc0005/hello-world
• [x] atc0005/mysql2sqlite
• [x] atc0005/nagios-debug
• [x] atc0005/query-meta
• [x] atc0005/safelinks
• [x] atc0005/send2teams
• [x] atc0005/tsm-pass

References

• https://github.com/atc0005/mysql2sqlite/pull/472/commits/789700f5397af7aad7b12c63deea26aa8a58d871
• https://github.com/atc0005/mysql2sqlite/pull/472

[atc0005]

NOTE: Checking the boxes for library projects (for now). Will hold off updating those until a feature from a newer Go release is needed.