refactor: log update info once

- umu-launcher was logging the Proton update message and assigning the same variables twice in the delta update path. Just keep the assignment operations to both the public and private mappings scoped to _get_delta

umu/umu_proton.py

@@ -80,10 +80,6 @@ def get_umu_proton(env: dict[str, str], session_pools: SessionPools) -> dict[str
         tmpdirs: SessionCaches = (Path(tmp), Path(tmpcache))
         compatdirs = (UMU_COMPAT, STEAM_COMPAT)
         if _get_delta(env, UMU_COMPAT, patch, assets, session_pools) is env:
-            log.info("%s is up to date", os.environ["PROTONPATH"])
-            os.environ["PROTONPATH"] = str(
-                UMU_COMPAT.joinpath(os.environ["PROTONPATH"])
-            )
             return env
         if _get_latest(env, compatdirs, tmpdirs, assets, session_pools) is env:
             return env
@@ -604,6 +600,12 @@ def _get_delta(
             orig.rename(new)
         log.debug("Update time (ns): %s", time.time_ns() - start)
 
+    # At this point, the update was successful. Assuming no bugs, this
+    # statement is expected to be incorrect if the user tampered with the build
+    log.info("%s is up to date", version)
+    os.environ["PROTONPATH"] = str(umu_compat.joinpath(version))
+    env["PROTONPATH"] = os.environ["PROTONPATH"]
+
     return env