Bump org.jenkins-ci.plugins:gitlab-oauth in /bom-weekly

Bumps [org.jenkins-ci.plugins:gitlab-oauth](https://github.com/jenkinsci/gitlab-oauth-plugin) from 1.19 to 1.20.
- [Release notes](https://github.com/jenkinsci/gitlab-oauth-plugin/releases)
- [Changelog](https://github.com/jenkinsci/gitlab-oauth-plugin/blob/master/CHANGELOG.md)
- [Commits](jenkinsci/gitlab-oauth-plugin@gitlab-oauth-1.19...gitlab-oauth-1.20)

---
updated-dependencies:
- dependency-name: org.jenkins-ci.plugins:gitlab-oauth
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

bom-weekly/pom.xml

@@ -757,7 +757,7 @@
       <dependency>
         <groupId>org.jenkins-ci.plugins</groupId>
         <artifactId>gitlab-oauth</artifactId>
-        <version>1.19</version>
+        <version>1.20</version>
       </dependency>
       <dependency>
         <groupId>org.jenkins-ci.plugins</groupId>