Harmonize TLS push file method signatures

Author: sinclert-canonical

src/charm.py

@@ -998,7 +998,7 @@ def _on_postgresql_pebble_ready(self, event: WorkloadEvent) -> None:
             return
 
         try:
-            self.push_tls_files_to_workload(container)
+            self.push_tls_files_to_workload()
             for ca_secret_name in self.tls.get_ca_secret_names():
                 self.push_ca_file_into_workload(ca_secret_name)
         except (PathError, ProtocolError) as e:
@@ -1895,10 +1895,9 @@ def _push_file_to_workload(self, container: Container, file_path: str, file_data
             group=WORKLOAD_OS_GROUP,
         )
 
-    def push_tls_files_to_workload(self, container: Container = None) -> bool:
+    def push_tls_files_to_workload(self) -> bool:
         """Uploads TLS files to the workload container."""
-        if container is None:
-            container = self.unit.get_container("postgresql")
+        container = self.unit.get_container("postgresql")
 
         key, ca, cert = self.tls.get_tls_files()