Add timeout of 300 to allow Pages job to complete

What does this MR do?

This test was passing in other pipelines but was failing in Staging as the Executor took just under 2 minutes to provision. Upping timeout to 300 to account for any timing variances.

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Closes #296937 (closed)