slack/sig-release: s/security-release-team/security-rel-team

When initially attempting to create this usergroup, its description
was too long for Slack to accept. The original group name exists...
somewhere... in Slack, but it's no longer possible to update it (despite
shortening the description in previous follow-ups).

Here we rename the group so it can be properly created by Tempelis.

Signed-off-by: Stephen Augustus <[email protected]>

Author: justaugustus

communication/slack-config/restrictions.yaml

@@ -34,7 +34,7 @@ restrictions:
     usergroups:
       - "^sig-release-"
       - "^release-"
-      - "^security-release-team$"
+      - "^security-rel-team$"
   - path: "sig-security/*.yaml"
     channels:
       - "^sig-security$"

communication/slack-config/sig-release/usergroups.yaml

@@ -85,7 +85,7 @@ usergroups:
   # Should match the membership of the following teams at all times:
   # - https://git.k8s.io/security/#product-security-committee-psc
   # - https://git.k8s.io/sig-release/release-managers.md#release-managers
-  - name: security-release-team
+  - name: security-rel-team
     long_name: Security Release Team
     description: >-
       Composite of Product Security Committee members and Release Managers. Ping