Add Free Threading support to CI (boto#3701)

* Add CI for Python 3.14t

* Adjust memory limits to handle free-threading builds

* Separate memory growth contstants for free threading

Author: nateprewitt

.github/workflows/run-crt-test.yml

@@ -19,7 +19,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ['3.10', '3.11', '3.12', '3.13', '3.14', '3.15-dev']
+        python-version: ['3.10', '3.11', '3.12', '3.13', '3.14', '3.14t', '3.15-dev']
         os: [ubuntu-latest, macOS-latest, windows-latest]
     env:
       PYO3_USE_ABI3_FORWARD_COMPATIBILITY: ${{ matrix.python-version == '3.15-dev' && '1' || '' }}

.github/workflows/run-tests.yml

@@ -19,7 +19,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ['3.10', '3.11', '3.12', '3.13', '3.14', '3.15-dev']
+        python-version: ['3.10', '3.11', '3.12', '3.13', '3.14', '3.14t', '3.15-dev']
         os: [ubuntu-latest, macOS-latest, windows-latest]
     env:
       PYO3_USE_ABI3_FORWARD_COMPATIBILITY: ${{ matrix.python-version == '3.15-dev' && '1' || '' }}

setup.py

@@ -63,5 +63,6 @@ def find_version(*file_paths):
         'Programming Language :: Python :: 3.12',
         'Programming Language :: Python :: 3.13',
         'Programming Language :: Python :: 3.14',
+        'Programming Language :: Python :: Free Threading :: 2 - Beta',
     ],
 )

tests/functional/leak/test_resource_leaks.py

@@ -10,6 +10,8 @@
 # distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
 # ANY KIND, either express or implied. See the License for the specific
 # language governing permissions and limitations under the License.
+import sysconfig
+
 from tests import BaseClientDriverTest
 
 
@@ -22,10 +24,15 @@ class TestDoesNotLeakMemory(BaseClientDriverTest):
     # a substantial amount of time to the total test run time.
     INJECT_DUMMY_CREDS = True
     # We're making up numbers here, but let's say arbitrarily
-    # that the memory can't increase by more than 13MB.
+    # that the memory can't increase by more than {SCALING_FACTOR} MBs.
 
-    # TODO: Attempt to bring this back to 10MB once Python 3.14 releases
-    MAX_GROWTH_BYTES = 13 * 1024 * 1024
+    if sysconfig.get_config_var("Py_GIL_DISABLED") == 1:
+        # Free-threaded Python objects require additional
+        # memory for per-object locks and synchronization.
+        SCALING_FACTOR = 16
+    else:
+        SCALING_FACTOR = 13
+    MAX_GROWTH_BYTES = SCALING_FACTOR * 1024 * 1024
 
     def test_create_single_client_memory_constant(self):
         self.cmd('create_client', 's3')