fix: support Python 3.14 (#5646)

* ci: support Python 3.14

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* fix: Python 3.14 name change

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* tests: fix expected output to handle Python 3.14

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* fix: tighten CLI and add color on 3.14+

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* tests: ignore failure on 3.14.0b1

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* fix: support Python 3.14.0b1 with interperters

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* Update test_multiple_interpreters.py

* Update test_multiple_interpreters.py

* fix: new breakage for 3.14 fixed

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* fix: handle empty annotations 3.14

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* fix: Python 3.14 may not create the annotations dict

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* fix: use PyUnstable_IsImmortal

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* fix: use sys._is_immortal

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* tests: ignore large values for refcount too

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* style: pre-commit fixes

* ci: enable all free-threaded builds

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* fix: patch for embed

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* Revert "fix: patch for embed"

This reverts commit c4226a0671.

* ci: drop new 3.xt additions

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* fix: logic issue, also add some comments

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* Update include/pybind11/pytypes.h

---------

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

.github/workflows/ci.yml

@@ -34,6 +34,7 @@ jobs:
         python:
         - '3.8'
         - '3.13'
+        - '3.14'
         - 'pypy-3.10'
         - 'pypy-3.11'
         - 'graalpy-24.2'
@@ -108,6 +109,9 @@ jobs:
           # No NumPy for PyPy 3.10 ARM
           - runs-on: macos-14
             python: 'pypy-3.10'
+          # Beta 1 broken for compiling on GHA (thinks it's free-threaded)
+          - runs-on: windows-2022
+            python: '3.14'
 
 
     name: "🐍 ${{ matrix.python }} • ${{ matrix.runs-on }} • x64 ${{ matrix.args }}"