[GHA] Automatically choose merge queue base branch in restore artifac…

…ts action (openvinotoolkit#26939)

To avoid failures in merge queue like
https://github.com/openvinotoolkit/openvino_tokenizers/actions/runs/11218446282/job/31182230856
without setting branch directly via action parameter in a workflow
(there is no built-in env var for that unfortunately)

.github/actions/common/artifact_utils.py

@@ -9,7 +9,9 @@
 def add_common_args(parser: argparse.ArgumentParser):
     parser.add_argument('-s', '--commit_sha', help='Commit hash for which artifacts were generated', required=True)
     parser.add_argument('-b', '--branch_name', help='Name of GitHub branch', required=False,
-                        default=os.getenv('GITHUB_BASE_REF') or os.getenv('GITHUB_REF_NAME'))
+                        default=os.getenv('GITHUB_BASE_REF') or
+                                os.getenv('MERGE_QUEUE_BASE_REF').replace('refs/heads/', '') or
+                                os.getenv('GITHUB_REF_NAME'))
     parser.add_argument('-e', '--event_name', help='Name of GitHub event', required=False,
                         default=os.getenv('GITHUB_EVENT_NAME'))
     parser.add_argument('--storage_root', help='Root path of the artifacts storage', required=False,

.github/actions/restore_artifacts/action.yml

@@ -60,3 +60,4 @@ runs:
         EVENT_PARAM: "-e ${{ inputs.event_name }}"
         TO_RESTORE: "-r ${{ inputs.to_restore }}"
         DEFAULT_TARGET_DIR: "${{ env.GITHUB_WORKSPACE }}/${{ inputs.storage_dir || inputs.platform }}"
+        MERGE_QUEUE_BASE_REF: "${{ github.event.merge_group.base_ref }}"

.github/actions/store_artifacts/action.yml

@@ -60,3 +60,4 @@ runs:
         EVENT_PARAM: "-e ${{ inputs.event_name }}"
         STORAGE_PARAM: "--storage_dir ${{ inputs.storage_dir }}"
         PLATFORM_PARAM: "--platform ${{ inputs.platform }}"
+        MERGE_QUEUE_BASE_REF: ""