github: update the python version for the macOS Qt 6 runner

Note that as github collapses the script it runs so there is no
indication that the error was coming from our second command test -x
rather than pip.

Author: ahayzen-kdab

.github/workflows/github-cxx-qt-tests.yml

@@ -347,7 +347,7 @@ jobs:
             qt_qpa_platform: cocoa
             compiler_cache_path: /Users/runner/Library/Caches/Mozilla.sccache
             sccache_log_path: /Users/runner/Library/Caches/Mozilla.sccache.log.txt
-            clang_format_path: /Users/runner/Library/Python/3.13/bin/clang-format
+            clang_format_path: /Users/runner/Library/Python/3.14/bin/clang-format
             cargo_dir: ~/.cargo
             cc: clang
             cxx: clang++