Updating PR templates with correct committers tags

[seth-shaw-unlv]

As highlighted by @whikloj on another issue, and discussed in today's meeting, some of the PR templates in the Islandora-Devops community repos (e.g. claw-playbook) use @Islandora-CLAW/committers (which won't work in that community) instead of @Islandora-Devpos/committers.

Fortunately, @manez graciously agreed to do updates as part of other PRs.

We should also review the list's members to ensure it is up-to-date.

[dannylamb]

Done!