Bump org.jenkins-ci.plugins:cloudbees-bitbucket-branch-source

Bumps [org.jenkins-ci.plugins:cloudbees-bitbucket-branch-source](https://github.com/jenkinsci/bitbucket-branch-source-plugin) from 914.vc8c12e22f10e to 921.v6a_215c8b_f095.
- [Release notes](https://github.com/jenkinsci/bitbucket-branch-source-plugin/releases)
- [Commits](https://github.com/jenkinsci/bitbucket-branch-source-plugin/commits)

---
updated-dependencies:
- dependency-name: org.jenkins-ci.plugins:cloudbees-bitbucket-branch-source
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

bom-weekly/pom.xml

@@ -684,7 +684,7 @@
       <dependency>
         <groupId>org.jenkins-ci.plugins</groupId>
         <artifactId>cloudbees-bitbucket-branch-source</artifactId>
-        <version>914.vc8c12e22f10e</version>
+        <version>921.v6a_215c8b_f095</version>
       </dependency>
       <dependency>
         <groupId>org.jenkins-ci.plugins</groupId>