Bump org.plumelib:plume-util from 1.9.0 to 1.9.3

Bumps [org.plumelib:plume-util](https://github.com/plume-lib/plume-util) from 1.9.0 to 1.9.3.
- [Release notes](https://github.com/plume-lib/plume-util/releases)
- [Changelog](https://github.com/plume-lib/plume-util/blob/master/CHANGELOG.md)
- [Commits](plume-lib/plume-util@v1.9.0...v1.9.3)

---
updated-dependencies:
- dependency-name: org.plumelib:plume-util
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

gradle/libs.versions.toml

@@ -3,7 +3,7 @@ junitVer = "5.10.3"
 guavaVer = "33.2.1-jre"
 jSpecifyConformanceTestVer = "0.0.0-SNAPSHOT"
 checkerFrameworkVer = "3.42.0-eisop3"
-plumeUtilVer = "1.9.0"
+plumeUtilVer = "1.9.3"
 
 [libraries]
 junit = { module = "org.junit.jupiter:junit-jupiter", version.ref = "junitVer" }