restrict workflows to otel repo (open-telemetry#1466)

Signed-off-by: Pierre Tessier <pierre@pierretessier.com>

Author: puckpuck

.github/workflows/assign-reviewers.yml

@@ -12,6 +12,7 @@ on:
 
 jobs:
   assign-reviewers:
+    if: github.repository == 'open-telemetry/opentelemetry-demo'
     runs-on: ubuntu-latest
     steps:
       - uses: dyladan/component-owners@main

.github/workflows/build-images.yml

@@ -21,6 +21,7 @@ on:
 
 jobs:
   build_and_push_images:
+    if: github.repository == 'open-telemetry/opentelemetry-demo'
     runs-on: ubuntu-latest
     permissions:
       contents: read

.github/workflows/release.yml

@@ -9,6 +9,7 @@ on:
 jobs:
   build_and_push_images:
     uses: ./.github/workflows/build-images.yml
+    if: github.repository == 'open-telemetry/opentelemetry-demo'
     with:
       push: true
       version: ${{ github.event.release.tag_name }}