Replace JSR-305 annotations with spotbugs annotations

[MarkEWaite]

Replace JSR-305 annotations with spotbugs annotations

• Please check if the PR fulfills these requirements

• [x] The commit message describes your change
• [x] Tests for the changes have been added if possible (for bug fixes / features)
• [x] Docs have been added / updated (for bug fixes / features)
• [x] Changes are mentioned in the changelog (for bug fixes / features) (not needed - behavior preserving change)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

Annotations for Nonnull, CheckForNull, and several others were proposed for Java as part of dormant Java specification request JSR-305. The proposal never became a part of standard Java.

Jenkins plugins should switch from using JSR-305 annotations to use Spotbugs annotations that provide the same semantics.

The mailing list discussion from James Nord describes the affected annotations and why they should be replaced with annotations that are actively maintained.

The "Improve a plugin" tutorial provides instructions to perform this change.

An OpenRewrite recipe is also available and is even better than the tutorial.

• What is the current behavior? (You can also link to an open issue here)

Confirmed that automated tests pass on Linux with Java 21.

• What is the new behavior (if this is a feature change)?

Confirmed that automated tests pass on Linux with Java 21.

• Does this PR introduce a breaking change? (What changes might users need to make in their setup due to this PR?)

No breaking change.

• Other information:

Not applicable