.github/workflows: don't run on forks

.github/workflows/docker.yml

@@ -8,6 +8,7 @@ on:
 jobs:
   build-and-push:
     runs-on: ubuntu-latest
+    if: github.repository == 'Alexays/Waybar'
     strategy:
       fail-fast: false # don't fail the other jobs if one of the images fails to build
       matrix:

.github/workflows/nix-update-flake-lock.yml

@@ -9,6 +9,7 @@ on:
 jobs:
   lockfile:
     runs-on: ubuntu-latest
+    if: github.repository == 'Alexays/Waybar'
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4