Fix versioning for release builds.

(cherry picked from commit 9019cbfd2b715c35da10ad7ed79d44ab81e57052)

.github/workflows/release.yml

@@ -29,6 +29,10 @@ jobs:
         # For some reason the shiboken2.abi3.dll is not found properly, so I copy it instead
         Copy-Item .\venv\Lib\site-packages\shiboken2\shiboken2.abi3.dll .\venv\Lib\site-packages\PySide2\ -Force
 
+    - name: Finalize version
+      run: |
+        New-Item -ItemType file final
+
     - name: mypy game
       run: |
         ./venv/scripts/activate

game/version.py

@@ -1,8 +1,17 @@
 from pathlib import Path
 
 
+def _build_version_string() -> str:
+    components = ["2.2.0"]
+    if Path("buildnumber").exists():
+        with open("buildnumber", "r") as file:
+            components.append(file.readline())
+
+    if not Path("final").exists():
+        components.append("preview")
+
+    return "-".join(components)
+
+
 #: Current version of Liberation.
-VERSION = "2.2.0"
-if Path("buildnumber").exists():
-    with open("buildnumber", "r") as file:
-        VERSION += f"-{file.readline()}"
+VERSION = _build_version_string()