Git Client Plugin 3.7.0

🐛 Bug fixes

• JENKINS-64913 - Label private key files on SELinux (#673) @jimklimov
• JENKINS-64913 - Reduce build log noise from fixSELinuxLabel() (#690) @jimklimov

📦 Dependency updates

• Require Jenkins 2.263.1 (#691) @MarkEWaite
• Bump jgit.version from 5.10.0.202012080955-r to 5.11.0.202103091610-r (#688) @dependabot
• Bump plugin from 4.15 to 4.17 (#657,#689) @dependabot
• Bump equalsverifier from 3.5 to 3.5.5 (#654,#656,#660,#664,#679) @dependabot
• Bump spotbugs from 4.2.0 to 4.2.2 (#662,#681) @dependabot
• Bump spotbugs-annotations from 4.2.0 to 4.2.2 (#659,#682) @dependabot
• Bump spotbugs-maven-plugin from 4.1.4 to 4.2.0 (#652) @dependabot

📝 Documentation updates

• Use controller to refer to the Jenkins server (#669) @MarkEWaite

👻 Maintenance

• Remove unused private boolean and imports (#687) @MarkEWaite
• Make git-client compatible with future guava (#686) @timja
• Cleanup getInstance() references (#683) @darinpope
• Use JGit 5.10.0 ls-remote to get symbolic refs (#651) @MarkEWaite

🚦 Tests

• JENKINS-60940 - Migrate GitAPITests from JUnit 3 to JUnit 4 (#666,#668,#670,#674,#675,#676,#677,#678,#685) @GAyan17
• Remove special case from JGit test (#671) @MarkEWaite