refactor(quality): drop imports repeated inside functions

tests/test_api_core.py

@@ -351,8 +351,6 @@ class TestLongJobLock(unittest.TestCase):
         self.api = PromptManagerAPI(db=database)
 
     def _run(self, coro):
-        import asyncio
-
         return asyncio.run(coro)
 
     def test_second_acquire_is_refused_until_first_releases(self):
@@ -825,8 +823,6 @@ class TestInstanceHelpers(FolderPathsFixture):
         self.addCleanup(setattr, GalleryConfig, "MONITORING_DIRECTORIES", orig_dirs)
 
     def _run(self, coro):
-        import asyncio
-
         return asyncio.run(coro)
 
     def test_run_in_executor_with_kwargs(self):

tests/test_library.py

@@ -143,8 +143,6 @@ class TestLibrary(unittest.TestCase):
             self.db.get_library_positive(positive, variant_limit=201)
 
     def test_sorts_keysets_survive_anchor_deletion_and_insertions_without_writes(self):
-        import sqlite3
-
         a = self.save("Alpha", rating=2, tags=["tag"])
         b = self.save("beta", rating=5)
         c = self.save("charlie")

utils/diagnostics.py

@@ -386,14 +386,9 @@ class GalleryDiagnostics:
         except ImportError:
             self.logger.error("   [FAIL] PIL (Pillow): NOT AVAILABLE")
 
-        # Check sqlite3
-        try:
-            import sqlite3
-
-            dependencies["sqlite3"] = True
-            self.logger.info(f"   [PASS] sqlite3: {sqlite3.sqlite_version}")
-        except ImportError:
-            self.logger.error("   [FAIL] sqlite3: NOT AVAILABLE")
+        # sqlite3 is imported at the top of this module, so it is always here.
+        dependencies["sqlite3"] = True
+        self.logger.info(f"   [PASS] sqlite3: {sqlite3.sqlite_version}")
 
         all_deps_ok = all(dependencies.values())