fix: require typing-extensions 4.14 on Python 3.15 and test floors the CI10 way (#300)

* fix: require typing-extensions 4.14 on Python 3.15 and test floors there

* fix: keep only the 3.15 typing-extensions floor and test floors the CI10 way

Author: lesnik512

.github/workflows/_checks.yml

@@ -138,8 +138,12 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.11", "3.12", "3.13", "3.14"]
+        python-version: ["3.11", "3.12", "3.13", "3.14", "3.15"]
         target: [free, fastapi, litestar, faststream, fastmcp]
+        # PyYAML ships no cp315 wheel yet, and the fastmcp and litestar stacks pull it.
+        exclude:
+          - {python-version: "3.15", target: fastmcp}
+          - {python-version: "3.15", target: litestar}
         # These `include` entries name an existing `target`, so each adds `extras` to that
         # target's five combinations rather than creating a job of its own. `free` carries
         # orjson because it belongs to no *-all extra and its floor is a wheel-availability
@@ -159,7 +163,10 @@ jobs:
       - run: uv python install ${{ matrix.python-version }}
       - run: uv venv --python ${{ matrix.python-version }}
       # Pinned with builds allowed, so a floor with no wheel fails the wheel-only install below.
-      - run: uv pip compile pyproject.toml ${{ matrix.extras }} --no-deps --resolution lowest-direct -o floors.txt
+      - if: matrix.python-version == '3.11'
+        run: uv pip compile pyproject.toml ${{ matrix.extras }} --no-deps --resolution lowest-direct -o floors.txt
+      - if: matrix.python-version != '3.11'
+        run: uv pip compile pyproject.toml ${{ matrix.extras }} --resolution lowest-direct --no-build -o floors.txt
       - run: uv pip install -r pyproject.toml ${{ matrix.extras }} --constraints floors.txt --no-build
       - run: uv pip install --no-deps .
       - name: Bootstrap at the floors

pyproject.toml

@@ -24,7 +24,10 @@ dependencies = [
     # Runtime use: `typing_extensions.TypedDict` (healthchecks), required by pydantic/FastAPI on
     # Python < 3.12 (`typing.TypedDict` is rejected there). Pure Python, so ft-friendly.
     # >=4.6 because 4.4 and 4.5 raise on import under Python >=3.12 (they subclass `typing.TypeVar`).
-    "typing-extensions>=4.6",
+    # 4.7 to 4.13 install on 3.15 and fail at import: they read `typing.no_type_check_decorator`,
+    # which 3.15 removed. 4.14 is the first release after them.
+    "typing-extensions>=4.6; python_version < '3.15'",
+    "typing-extensions>=4.14; python_version >= '3.15'",
 ]
 
 [project.urls]