Support Java 17+ for Linkage Checker

Running Linkage Checker with Java 17+ results in compilation issue:
```
[INFO] Reactor Summary:
[INFO]
[INFO] Google Cloud Platform Supported Libraries 25.3.1-SNAPSHOT SUCCESS [ 0.049 s]
[INFO] Google Cloud Long Term Support BOM 8.0.0-SNAPSHOT .. SUCCESS [ 0.049 s]
[INFO] BOM Parent 1.0-SNAPSHOT ............................ SUCCESS [ 0.049 s]
[INFO] Cloud Platform Supported Libraries Upper Bounds Check 2.0.0-SNAPSHOT SUCCESS [ 0.353 s]
[INFO] Cloud Tools Open Source Code Hygiene Tooling 1.5.14-SNAPSHOT SUCCESS [ 0.206 s]
[INFO] Maven Dependency Graph Analyzer 1.5.14-SNAPSHOT .... FAILURE [ 0.952 s]
[INFO] integration-tests 1.2.0-SNAPSHOT ................... SKIPPED
[INFO] Cloud Tools Open Source Code Hygiene Dashboard 1.5.14-SNAPSHOT SKIPPED
[INFO] Linkage Checker Enforcer Rule 1.5.14-SNAPSHOT ...... SKIPPED
[INFO] Linkage Monitor 1.5.14-SNAPSHOT .................... SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.359 s (Wall Clock)
[INFO] Finished at: 2025-02-24T17:03:52-05:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project dependencies: Compilation failure -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException
[ERROR]
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR] mvn -rf :dependencies
```