Stop building an image for each merge on main

.github/workflows/build-image.yml

@@ -2,8 +2,6 @@ name: Build container image
 on:
   workflow_dispatch:
   push:
-    branches:
-      - 'main'
     tags:
       - '*'
   pull_request:
@@ -16,7 +14,7 @@ permissions:
 
 jobs:
   build-image:
-    runs-on: ubuntu-latest
+    runs-on: docker-builder
 
     concurrency:
       group: ${{ github.workflow }}-${{ github.ref }}

.github/workflows/build-nightly.yml

@@ -9,7 +9,7 @@ permissions:
 
 jobs:
   build-nightly-image:
-    runs-on: ubuntu-latest
+    runs-on: docker-builder
 
     concurrency:
       group: ${{ github.workflow }}-${{ github.ref }}
@@ -37,6 +37,7 @@ jobs:
             latest=auto
           tags: |
             type=raw,value=nightly
+            type=raw,value=edge
             type=schedule,pattern=nightly-{{date 'YYYY-MM-DD' tz='Etc/UTC'}}
           labels: |
             org.opencontainers.image.description=Nightly build image used for testing purposes