chore(toolchains): start pulling toolchains from 20250808 release (bazel-contrib#3116)

This ships the latest versions of the toolchains fixing:

* `bootstrap_impl=script` behaviour on `3.14`.
* `matplotlib` UI with the latest Python toolchain versions.

Fixes bazel-contrib#2983
Fixes bazel-contrib#2540
Related bazel-contrib#3155

Author: aignas

CHANGELOG.md

@@ -60,13 +60,13 @@ END_UNRELEASED_TEMPLATE
 * (gazelle) Types for exposed members of `python.ParserOutput` are now all public.
 * (gazelle) Removed the requirement for `__init__.py`, `__main__.py`, or `__test__.py` files to be
   present in a directory to generate a `BUILD.bazel` file.
-* (toolchain) Updated the following toolchains to build 20250708 to patch CVE-2025-47273:
+* (toolchain) Updated the following toolchains to build [20250808] to patch CVE-2025-47273:
     * 3.9.23
     * 3.10.18
     * 3.11.13
     * 3.12.11
-    * 3.14.0b4
-* (toolchain) Python 3.13 now references 3.13.5
+    * 3.14.0rc1
+* (toolchain) Python 3.13 now references 3.13.6
 * (gazelle) Switched back to smacker/go-tree-sitter, fixing
   [#2630](https://github.com/bazel-contrib/rules_python/issues/2630)
 * (ci) We are now testing on Ubuntu 22.04 for RBE and non-RBE configurations.
@@ -75,6 +75,8 @@ END_UNRELEASED_TEMPLATE
   {gh-path}`gazelle/docs` and are now available on the primary documentation site
   at https://rules-python.readthedocs.io/en/latest/gazelle/docs/index.html
 
+[20250808]: https://github.com/astral-sh/python-build-standalone/releases/tag/20250808
+
 {#v0-0-0-fixed}
 ### Fixed
 * (pypi) Fixes an issue where builds using a `bazel vendor` vendor directory
@@ -126,8 +128,8 @@ END_UNRELEASED_TEMPLATE
 * (toolchain) Add toolchains for aarch64 windows for
     * 3.11.13
     * 3.12.11
-    * 3.13.5
-    * 3.14.0b4
+    * 3.13.6
+    * 3.14.0rc1
 * (gazelle): New annotation `gazelle:include_pytest_conftest`. When not set (the
   default) or `true`, gazelle will inject any `conftest.py` file found in the same
   directory as a {obj}`py_test` target to that {obj}`py_test` target's `deps`.

python/private/hermetic_runtime_repo_setup.bzl

@@ -239,6 +239,7 @@ def define_hermetic_runtime_toolchain_impl(
     py_cc_toolchain(
         name = "py_cc_toolchain",
         headers = ":python_headers",
+        # TODO #3155: add libctl, libtk
         libs = ":libpython",
         python_version = python_version,
     )