Split NO_EXT tests into sync and async

Author: blink1073

.evergreen/generated_configs/variants.yml

@@ -772,7 +772,7 @@ buildvariants:
   # No c ext tests
   - name: no-c-ext-rhel8-python3.9
     tasks:
-      - name: .standalone .noauth .nossl .sync_async
+      - name: .standalone .noauth .nossl !.sync_async
     display_name: No C Ext RHEL8 Python3.9
     run_on:
       - rhel87-small
@@ -781,7 +781,7 @@ buildvariants:
       PYTHON_BINARY: /opt/python/3.9/bin/python3
   - name: no-c-ext-rhel8-python3.10
     tasks:
-      - name: .replica_set .noauth .nossl .sync_async
+      - name: .replica_set .noauth .nossl !.sync_async
     display_name: No C Ext RHEL8 Python3.10
     run_on:
       - rhel87-small
@@ -790,7 +790,7 @@ buildvariants:
       PYTHON_BINARY: /opt/python/3.10/bin/python3
   - name: no-c-ext-rhel8-python3.11
     tasks:
-      - name: .sharded_cluster .noauth .nossl .sync_async
+      - name: .sharded_cluster .noauth .nossl !.sync_async
     display_name: No C Ext RHEL8 Python3.11
     run_on:
       - rhel87-small
@@ -799,7 +799,7 @@ buildvariants:
       PYTHON_BINARY: /opt/python/3.11/bin/python3
   - name: no-c-ext-rhel8-python3.12
     tasks:
-      - name: .standalone .noauth .nossl .sync_async
+      - name: .standalone .noauth .nossl !.sync_async
     display_name: No C Ext RHEL8 Python3.12
     run_on:
       - rhel87-small
@@ -808,7 +808,7 @@ buildvariants:
       PYTHON_BINARY: /opt/python/3.12/bin/python3
   - name: no-c-ext-rhel8-python3.13
     tasks:
-      - name: .replica_set .noauth .nossl .sync_async
+      - name: .replica_set .noauth .nossl !.sync_async
     display_name: No C Ext RHEL8 Python3.13
     run_on:
       - rhel87-small

.evergreen/scripts/generate_config.py

@@ -588,7 +588,7 @@ def create_no_c_ext_variants():
     variants = []
     host = DEFAULT_HOST
     for python, topology in zip_cycle(CPYTHONS, TOPOLOGIES):
-        tasks = [f".{topology} .noauth .nossl .sync_async"]
+        tasks = [f".{topology} .noauth .nossl !.sync_async"]
         expansions = dict()
         handle_c_ext(C_EXTS[0], expansions)
         display_name = get_display_name("No C Ext", host, python=python)

.evergreen/scripts/setup_tests.py

@@ -21,7 +21,7 @@
 ROOT = HERE.parent.parent
 ENV_FILE = HERE / "test-env.sh"
 DRIVERS_TOOLS = os.environ.get("DRIVERS_TOOLS", "").replace(os.sep, "/")
-PLATFORM = "windows" if os.name == "nt" else sys.platform
+PLATFORM = "windows" if os.name == "nt" else sys.platform.lower()
 
 LOGGER = logging.getLogger(__name__)
 logging.basicConfig(level=logging.INFO, format="%(levelname)-8s %(message)s")
@@ -230,7 +230,7 @@ def handle_test_env() -> None:
     write_env("SSL", SSL)
 
     # Skip CSOT tests on non-linux platforms.
-    if sys.platform != "Linux":
+    if PLATFORM != "linux":
         write_env("SKIP_CSOT_TESTS")
 
     # Set an environment variable for the test name and sub test name.