Improve cache-clean action, remove cache-rebuild

Select level of cleaning required
Rebuild happens in due course, no need for a specific action.

.github/workflows/cache-clean.yml

@@ -2,6 +2,16 @@ name: Cache clean
 
 on:
   workflow_dispatch:
+    inputs:
+      clean_opt:
+        description: 'Level of cleaning required'
+        type: choice
+        default: push-requests
+        options:
+          - pull-requests
+          - ccache
+          - idf-tools
+          - ccache+idf
 
 jobs:
   cleanup:
@@ -12,7 +22,26 @@ jobs:
           gh extension install actions/gh-actions-cache
 
           echo "Fetching list of cache keys"
-          cacheKeys=$(gh actions-cache list -R $REPO -L 100 | grep -v develop | cut -f 1 )
+          case $CLEAN_OPT in
+            pull-requests)
+              filter="-v develop"
+              ;;
+            ccache)
+              filter="ccache"
+              ;;
+            idf-tools)
+              filter="idf"
+              ;;
+            ccache+idf)
+              filter="ccache\|idf"
+              ;;
+            *)
+              echo "Unknown option '$CLEAN_OPT'"
+              exit 1
+              ;;
+          esac
+
+          cacheKeys=$(gh actions-cache list -R $REPO -L 100 | grep $filter | cut -f 1 )
 
           echo "Deleting caches..."
           set +e
@@ -23,3 +52,4 @@ jobs:
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           REPO: ${{ github.repository }}
+          CLEAN_OPT: ${{ inputs.clean_opt }}

Tools/ci/README.rst

@@ -7,11 +7,31 @@ Github actions
 See ``.github/workflows``.
 
 Cache clean
-      Dispatch workflow to remove caches for pull requests, but leave those for the default (develop) branch intact.
+      Dispatch workflow as convenient way to clean action cache. Cleaning levels are:
+
+      - pull-requests
+            Any items created by pull requests, excludes anything in develop branch.
+            Normally pull requests will make use of caches present in the develop branch, but if there isn't one it will create its own. This becomes redundant when merged to develop.
+
+            Such caches should be expired automatically, but this option can be used to remove them.
+
+      - ccache
+            All ccache items. Use if pull requests are taking too long to build.
+
+      - idf-tools
+            All IDF tool. Use before merging to develop if IDF toolchains have been updated.
+
+      - ccache+idf
+            All ccache and IDF tool caches.
+
+      Note that cleaning can always be done locally using ``gh``::
+
+            gh cache list # For fork
+            gh cache list -R SmingHub/Sming
+            gh cache delete --all -R SmingHub/Sming
+
+      etc.
 
-Cache rebuild
-      Dispatch workflow to rebuild the esp32 idf/tool caches.
-      By default, cleans only idf/esp32 caches but has option to perform full clean.
 
 CodeQL
       Performs code quality analysis when develop branch is updated.