Modernize and pin packaging workflow

Rename main.yml to release.yml to reflect that it packages the plugin and
publishes the auto-release. Name the job and the previously unnamed step,
strip trailing whitespace, and pin every action to a commit SHA (with a
version comment) at its latest release:

- actions/checkout v2 -> v7.0.0
- actions/upload-artifact v4 -> v7.0.1
- dev-drprasad/delete-older-releases v0.2.1 -> v0.3.4
- softprops/action-gh-release v1 -> v3.0.1

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.github/workflows/release.yml

@@ -5,29 +5,30 @@ on:
 
 jobs:
   package:
+    name: Package and auto-release
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
       - name: Package
         run: python3 make_release.py
 
       - name: Upload
-        uses: actions/upload-artifact@v4
-        with: 
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
           name: plugin
           path: |
             DeDRM_tools_*.zip
             DeDRM_tools.zip
-     
+
       - name: Prepare release
         run: cp DeDRM_tools.zip DeDRM_alpha_${{ github.sha }}.zip
 
-
-      - uses: dev-drprasad/delete-older-releases@v0.2.1
+      - name: Delete older auto-releases
+        uses: dev-drprasad/delete-older-releases@dfbe6be2a006e9475dfcbe5b8d201f1824c2a9fe # v0.3.4
         with:
-          repo: noDRM/DeDRM_tools_autorelease 
+          repo: noDRM/DeDRM_tools_autorelease
           keep_latest: 0
           delete_tags: true
         env:
@@ -35,14 +36,14 @@ jobs:
 
       - name: Auto-release
         id: autorelease
-        uses: softprops/action-gh-release@v1
-        with: 
+        uses: softprops/action-gh-release@718ea10b132b3b2eba29c1007bb80653f286566b # v3.0.1
+        with:
           tag_name: autorelease_${{ github.sha }}
           repository: noDRM/DeDRM_tools_autorelease
           token: ${{ secrets.AUTORELEASE_KEY }}
           name: Automatic alpha release with latest changes
           body: |
-            This release is automatically generated by Github for each commit. 
+            This release is automatically generated by Github for each commit.
 
             This means, every time a change is made to the repo, a release with an untested copy of the plugin at that stage will be created. This will contain the most up-to-date code, but it's not tested at all and may be broken.