feat: support config-free ERP app versioning

action.yml

@@ -1,14 +1,9 @@
 name: Bump ERP app version
 description: Bump a Frappe/ERPNext app version on a release branch using bump-my-version
 inputs:
-  config-file:
-    description: Path to the bump-my-version TOML configuration
-    required: false
-    default: pyproject.toml
   version-file:
-    description: App __init__.py used to bootstrap when the base branch has no bump-my-version config
-    required: false
-    default: ""
+    description: App __init__.py containing a stable MAJOR.MINOR.PATCH __version__ assignment
+    required: true
   base-branch:
     description: Branch whose version is used as the release baseline
     required: false
@@ -65,7 +60,6 @@ runs:
       id: bump
       shell: bash
       env:
-        INPUT_CONFIG_FILE: ${{ inputs.config-file }}
         INPUT_VERSION_FILE: ${{ inputs.version-file }}
         INPUT_BASE_BRANCH: ${{ inputs.base-branch }}
         INPUT_TARGET_BRANCH: ${{ inputs.target-branch }}