Maint: CI changes

- Only trigger on push and PR to master
- Do not push images for branches
- Add fork only workflow
- Add dependabot only workflow
- Do not trigger ci workflow from forked/dependabot PRs

.github/workflows/ci.yml

@@ -1,6 +1,21 @@
 name: CI
 on:
   push:
+    branches:
+      - master
+    paths:
+      - .github/workflows/ci.yml
+      - cmd/**
+      - internal/**
+      - pkg/**
+      - .dockerignore
+      - .golangci.yml
+      - Dockerfile
+      - go.mod
+      - go.sum
+  pull_request:
+    branches:
+      - master
     paths:
       - .github/workflows/ci.yml
       - cmd/**
@@ -14,6 +29,7 @@ on:
 
 jobs:
   verify:
+    if: github.event.pull_request.head.repo.full_name == github.repository
     runs-on: ubuntu-latest
     env:
       DOCKER_BUILDKIT: "1"
@@ -52,6 +68,7 @@ jobs:
           image: final-image
 
   publish:
+    if: github.event.pull_request.head.repo.full_name == github.repository
     needs: [verify]
     runs-on: ubuntu-latest
     steps:
@@ -70,18 +87,14 @@ jobs:
         env:
           EVENT_NAME: ${{ github.event_name }}
         run: |
-          BRANCH=${GITHUB_REF#refs/heads/}
           TAG=${GITHUB_REF#refs/tags/}
           echo ::set-output name=commit::$(git rev-parse --short HEAD)
           echo ::set-output name=created::$(date -u +%Y-%m-%dT%H:%M:%SZ)
           if [ "$TAG" != "$GITHUB_REF" ]; then
             echo ::set-output name=version::$TAG
             echo ::set-output name=platforms::linux/amd64,linux/386,linux/arm64,linux/arm/v6,linux/arm/v7,linux/ppc64le
-          elif [ "$BRANCH" = "master" ]; then
-            echo ::set-output name=version::latest
-            echo ::set-output name=platforms::linux/amd64,linux/386,linux/arm64,linux/arm/v6,linux/arm/v7,linux/ppc64le
           else
-            echo ::set-output name=version::$BRANCH
+            echo ::set-output name=version::latest
             echo ::set-output name=platforms::linux/amd64,linux/386,linux/arm64,linux/arm/v6,linux/arm/v7,linux/ppc64le
           fi