restore platformio envs and CI python baseline

.github/workflows/ci.yml

@@ -25,7 +25,7 @@ jobs:
       - name: Setup Python
         uses: actions/setup-python@v5
         with:
-          python-version: "3.11"
+          python-version: "3.12"
 
       - name: Bootstrap repo-local venv
         run: bash tools/bootstrap_python_env.sh

firmware/platformio.ini

@@ -30,7 +30,7 @@ lib_deps =
     https://github.com/esp-arduino-libs/esp-lib-utils.git#v0.2.0
     https://github.com/esp-arduino-libs/ESP32_IO_Expander.git#v1.1.0
     https://github.com/esp-arduino-libs/ESP32_Display_Panel.git#v1.0.4
-    https://github.com/schreibfaul1/ESP32-audioI2S
+    https://github.com/schreibfaul1/ESP32-audioI2S/archive/refs/heads/master.zip
 
 [env:esp32s3_qemu]
 ; Same as waveshare but without PSRAM (QEMU doesn't emulate octal PSRAM)