Fix group search API requests for gitlab-org with commits scope timing out in database

Problem

Group search API requests for gitlab-org with commits scope are timing out in the database with no Elasticsearch duration. These requests are not using advanced search, causing database-only queries that are slow and contributing to error budget violations.

Key Findings

• Group search API requests for gitlab-org are timing out in the database
• No Elasticsearch duration is recorded for these requests
• commits scope is the only scope affected by this issue
• Commits scope for gitlab-org is not using advanced search in the search API
• This is not a recent regression - it's been happening for longer than the recent feature flag rollout
• These requests are contributing to high response times and SLI violations

Root Cause

The commits scope for gitlab-org is not configured to use advanced search (Elasticsearch/Zoekt), forcing all queries to go through the database only.

Investigation Areas

• Determine why commits scope for gitlab-org is not using advanced search
• Verify if this is a configuration issue or a code issue
• Check if other groups/projects have the same problem
• Implement advanced search support for commits scope queries

Related Issue

See gitlab-org/search-team/team-tasks#265 for full context and investigation details.