* ci: use StepSecurity's maintained actions
Each third-party action that StepSecurity publishes a secure drop-in
replacement for now uses that replacement, pinned to a commit with its
version as a comment. Versions follow what we used: the newest
StepSecurity release in the same major, or the closest major they
publish. dtolnay/rust-toolchain refs that named a toolchain (stable,
nightly, 1.76) become the replacement's `toolchain` input.
* tests: find the FreeBSD VM, SonarCloud scan and install-action steps by their StepSecurity names
Dylan M. Taylor
coderabbitai[bot]