ci: Streamline the old MacOS-12 CI test

It's an old flavor not well supported by homebrew any longer, so
what's happening is that most of the dependency packages we ask to
install have to build from source, which means it takes a long long
time.

By disabling OpenCV and Qt homebrew installation for it, we can make
it fast again. Neither the minimal OpenCV interop, nor osltoy (the
only thing that needs Qt) are exercised by the automated testsuite
anyway, so I don't think there's any loss of testing functionality
in practice.

Signed-off-by: Larry Gritz <lg@larrygritz.com>

.github/workflows/ci.yml

@@ -512,8 +512,9 @@ jobs:
             cc_compiler: clang
             cxx_compiler: clang++
             cxx_std: 17
-            python_ver: "3.10"
+            python_ver: "3.11"
             aclang: 13
+            setenvs: export INSTALL_QT=0 INSTALL_OPENCV=0
           - desc: MacOS-13
             runner: macos-13
             nametag: macos13-py311
@@ -525,11 +526,11 @@ jobs:
             simd: sse4.2,avx2
           - desc: MacOS-14-ARM
             runner: macos-14
-            nametag: macos14-arm-py311
+            nametag: macos14-arm-py312
             cc_compiler: clang
             cxx_compiler: clang++
             cxx_std: 20
-            python_ver: "3.11"
+            python_ver: "3.12"
             aclang: 15
     runs-on: ${{ matrix.runner }}
     env:

src/build-scripts/install_homebrew_deps.bash

@@ -44,10 +44,10 @@ brew install --display-times -q freetype libraw dcmtk pybind11 numpy || true
 brew install --display-times -q ffmpeg libheif ptex || true
 brew install --display-times -q tbb || true
 brew install --display-times -q openvdb || true
-if [[ "${USE_OPENCV}" != "0" ]] ; then
+if [[ "${USE_OPENCV}" != "0" ]] && [[ "${INSTALL_OPENCV:=1}" != "0" ]] ; then
     brew install --display-times -q opencv || true
 fi
-if [[ "${USE_QT}" != "0" ]] ; then
+if [[ "${USE_QT:=1}" != "0" ]] && [[ "${INSTALL_QT:=1}" != "0" ]] ; then
     brew install --display-times -q qt${QT_VERSION}
 fi
 if [[ "${USE_LLVM:=0}" != "0" ]] || [[ "${LLVMBREWVER}" != "" ]]; then