Remove incorrect annotation on GitSCM.getBrowser() - #1731

Remove incorrect annotation on GitSCM.getBrowser()

Jesse Glick notes in JENKINS-75288:

adding @Whitelisted to a method already marked @Override is clearly a mistake—this would never have any effect.

I didn't realize that was a mistake when I added the annotation. Let's remove the annotation so that the code does not mislead someone to think that this can be used from a Pipeline without changes to hudson.scm.SCM.getBrowser().

In a multibranch Pipeline, the default checkout assigns current values to the scm object, including scm.browser. That value can't be read unless the hudson.scm.SCM.getBrowser() method is approved through script security.

Testing done

None. Already confirmed that the annotation has no effect, as noted in JENKINS-75288. Removing the annotation will continue to have no effect.

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests - that demonstrates feature works or fixes the issue