Dedup pyinstaller actions.

.github/actions/build-app/action.yaml

@@ -0,0 +1,22 @@
+name: Build Liberation package
+description: Assembles the full Liberation application.
+runs:
+  using: composite
+  steps:
+    - name: Build client
+      shell: powershell
+      run: |
+        cd client
+        npm run build
+
+    - name: Build binaries
+      shell: powershell
+      run: |
+        ./venv/scripts/activate
+        $env:PYTHONPATH=".;./pydcs"
+        pyinstaller pyinstaller.spec
+
+    - name: Install changelog
+      shell: powershell
+      run: |
+        Copy-Item .\changelog.md .\dist

.github/actions/build-front-end/action.yaml

@@ -1,10 +0,0 @@
-name: Front-end build
-description: Builds the Liberation front-end.
-runs:
-  using: composite
-  steps:
-    - name: Build client
-      shell: powershell
-      run: |
-        cd client
-        npm run build