stop github actions from sending me mail

Currently github actions keep sending me mails about things that should
only run on the prometheus organisation actions. This change makes sure
to check who owns the repository before running the CI workflow.

Signed-off-by: Francis Begyn <francis@begyn.be>

.github/workflows/buf.yml

@@ -7,6 +7,7 @@ jobs:
   buf:
     name: lint and publish
     runs-on: ubuntu-latest
+    if: github.repository_owner == 'prometheus'
     steps:
       - uses: actions/checkout@v3
       - uses: bufbuild/buf-setup-action@v1.13.1

.github/workflows/lock.yml

@@ -14,6 +14,7 @@ concurrency:
 jobs:
   action:
     runs-on: ubuntu-latest
+    if: github.repository_owner == 'prometheus'
     steps:
       - uses: dessant/lock-threads@v4
         with:

.github/workflows/repo_sync.yml

@@ -6,6 +6,7 @@ on:
 jobs:
   repo_sync:
     runs-on: ubuntu-latest
+    if: github.repository_owner == 'prometheus'
     container:
       image: quay.io/prometheus/golang-builder
     steps: