github/workflows: Include the Python version in the ESP-IDF cache key.

Changing runner OS can change Python version, and ESP-IDF installs are
keyed on ESP-IDF and Python version together.

Signed-off-by: Angus Gratton <angus@redyak.com.au>

.github/workflows/ports_esp32.yml

@@ -30,8 +30,8 @@ jobs:
     - uses: actions/checkout@v4
 
     - id: idf_ver
-      name: Read the ESP-IDF version
-      run: source tools/ci.sh && echo "IDF_VER=$IDF_VER" | tee "$GITHUB_OUTPUT"
+      name: Read the ESP-IDF version (including Python version)
+      run: source tools/ci.sh && echo "IDF_VER=${IDF_VER}-py${PYTHON_VER}" | tee "$GITHUB_OUTPUT"
 
     - name: Cached ESP-IDF install
       id: cache_esp_idf

tools/ci.sh

@@ -140,6 +140,7 @@ function ci_cc3200_build {
 
 # GitHub tag of ESP-IDF to use for CI (note: must be a tag or a branch)
 IDF_VER=v5.2.2
+PYTHON_VER=$(python --version | cut -d' ' -f2)
 
 export IDF_CCACHE_ENABLE=1