Skip remote extensions WITH_LIB test when sanitizers are enabled (#11758)

In order for the test to work when sanitizers are enabled, we would need
to compile the dummy Postgres extension with the same sanitizer flags
that we compile Postgres and the neon extension with. Doing this work
would be a little more than trivial, so skipping is the best option, at
least for now.

Signed-off-by: Tristan Partin <tristan@neon.tech>

test_runner/regress/test_download_extensions.py

@@ -14,7 +14,7 @@ from fixtures.log_helper import log
 from fixtures.metrics import parse_metrics
 from fixtures.paths import BASE_DIR
 from fixtures.pg_config import PgConfigKey
-from fixtures.utils import subprocess_capture
+from fixtures.utils import WITH_SANITIZERS, subprocess_capture
 from werkzeug.wrappers.response import Response
 
 if TYPE_CHECKING:
@@ -148,6 +148,15 @@ def test_remote_extensions(
     pg_config: PgConfig,
     extension: RemoteExtension,
 ):
+    if WITH_SANITIZERS and extension is RemoteExtension.WITH_LIB:
+        pytest.skip(
+            """
+            For this test to work with sanitizers enabled, we would need to
+            compile the dummy Postgres extension with the same CFLAGS that we
+            compile Postgres and the neon extension with to link the sanitizers.
+            """
+        )
+
     # Setup a mock nginx S3 gateway which will return our test extension.
     (host, port) = httpserver_listen_address
     extensions_endpoint = f"http://{host}:{port}/pg-ext-s3-gateway"