chore(deps): bump io.jenkins.plugins:theme-manager in /bom-weekly (#4272)

Bumps [io.jenkins.plugins:theme-manager](https://github.com/jenkinsci/theme-manager-plugin) from 276.vdec9cf04f928 to 278.v2e3c063e42cc.
- [Release notes](https://github.com/jenkinsci/theme-manager-plugin/releases)
- [Commits](https://github.com/jenkinsci/theme-manager-plugin/commits)

---
updated-dependencies:
- dependency-name: io.jenkins.plugins:theme-manager
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

bom-weekly/pom.xml

@@ -574,7 +574,7 @@
       <dependency>
         <groupId>io.jenkins.plugins</groupId>
         <artifactId>theme-manager</artifactId>
-        <version>276.vdec9cf04f928</version>
+        <version>278.v2e3c063e42cc</version>
       </dependency>
       <dependency>
         <groupId>io.jenkins.plugins</groupId>