Switch development branch from 1.21 series to specific point release

[atc0005]

Overview

Dependabot recently switched from the 1.21 release candidates to the 1.21 series (and not to a specific point release). This broke the "canary" PR behavior for the development branch.

Update that branch for applicable projects to use the 1.21.0 release in order to switch from a "series" version specifier to a point release. This also confirms that Dependabot monitoring will update from 1.21.0 to 1.21.1 as intended.

TODO

NOTE: Go ahead and check the box for any non-applicable projects.

• [x] atc0005/brick
• [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-ezproxy
• [x] atc0005/go-lockss
• [x] atc0005/go-template
• [x] atc0005/hello-world
• [x] atc0005/mysql2sqlite
• [x] atc0005/go-nagios
• [x] atc0005/go-teams-notify
• [x] atc0005/nagios-debug
• [x] atc0005/query-meta
• [x] atc0005/safelinks
• [x] atc0005/send2teams
• [x] atc0005/tsm-pass