Update session_token rule for Runner tokens

What does this MR do and why?

Based on gitlab-org/gitlab#523581 (comment 2408706798), and follow-up Move partition_id to token payload (gitlab-org/gitlab!183554 - merged), we're updating session_token rule for Runners.

With this change, we're supporting the following prefixes:

• glrt-TOKEN
• glrtr-TOKEN

References

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• Move runner partition prefix to routable payload (gitlab-org/gitlab#523581 - closed)

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