ci.yml now pins PIOArduino Core to v6.1.19, replaces deprecated pio platform install

Author: zekageri

.github/workflows/ci.yml

@@ -41,15 +41,15 @@ jobs:
         uses: actions/cache@v4
         with:
           path: ~/.platformio
-          key: ${{ runner.os }}-platformio-${{ hashFiles('**/library.json') }}
+          key: ${{ runner.os }}-platformio-pioarduino-6.1.19-${{ hashFiles('**/library.json') }}
           restore-keys: |
-            ${{ runner.os }}-platformio-
+            ${{ runner.os }}-platformio-pioarduino-6.1.19-
 
       - name: Install PIOArduino Core
-        run: python -m pip install --upgrade https://github.com/pioarduino/platformio-core/archive/refs/tags/v6.1.18.zip
+        run: python -m pip install --upgrade https://github.com/pioarduino/platformio-core/archive/refs/tags/v6.1.19.zip
 
       - name: Install PIOArduino ESP32 Platform
-        run: pio platform install https://github.com/pioarduino/platform-espressif32.git
+        run: pio pkg install -g -p https://github.com/pioarduino/platform-espressif32.git
 
       - name: Build library examples (ESP32 Arduino)
         run: |

CHANGELOG.md

@@ -17,6 +17,7 @@ The format follows Keep a Changelog and the project adheres to Semantic Versioni
 - Ensured per-second and per-minute countdown timers emit their final tick by rounding up remaining time.
 - Added lifecycle test coverage for pre-init `deinit()`, repeated `deinit()`, and `init -> deinit -> init` reinitialization.
 - Removed library-owned exception/abort paths from timer allocation and callback dispatch, and guarded lifecycle state/ID generation behind a persistent mutex for task-safe use.
+- CI now pins PIOArduino Core to `v6.1.19` and installs the ESP32 platform via `pio pkg install`, restoring PlatformIO compatibility with the current `platform-espressif32` package.
 
 ### Documentation
 - Added an MIT license badge and cross-links to other ESPToolKit libraries in the README.