ci: Add fallback for build context

Author: osipxd

.github/workflows/android-emu.yml

@@ -10,7 +10,6 @@ jobs:
     uses: ./.github/workflows/publish-image.yml
     with:
       image-name: android-emu
-      context: android-emu
       title: Android Emulator image
       tags: |
         ${{ matrix.version }}

.github/workflows/android-sdk.yml

@@ -33,7 +33,6 @@ jobs:
     uses: ./.github/workflows/publish-image.yml
     with:
       image-name: ${{ needs.env.outputs.image-name }}
-      context: android-sdk
       target: base
       platforms: linux/amd64,linux/arm64
       title: Android SDK base image

.github/workflows/danger-kotlin.yml

@@ -10,7 +10,6 @@ jobs:
     uses: ./.github/workflows/publish-image.yml
     with:
       image-name: danger-kotlin
-      context: danger-kotlin
       title: Danger Kotlin image
       tags: |
         ${{ matrix.version }}

.github/workflows/publish-image.yml

@@ -11,7 +11,6 @@ on:
         description: 'Location of build files'
         required: false
         type: string
-        default: '-'
       title:
         description: 'Human-readable image title'
         required: true
@@ -78,7 +77,7 @@ jobs:
       - name: Build and push Docker images
         uses: docker/build-push-action@v5
         with:
-          context: ${{ inputs.context }}
+          context: ${{ inputs.context != null && inputs.context || inputs.image-name }}
           push: true
           build-args: ${{ inputs.build-args }}
           build-contexts: ${{ inputs.build-contexts }}

.github/workflows/ruby.yml

@@ -10,7 +10,6 @@ jobs:
     uses: ./.github/workflows/publish-image.yml
     with:
       image-name: ruby
-      context: ruby
       platforms: linux/amd64
       title: Ruby image
       tags: |