Revert "Fix regression: report size delta size on PR. (#429)"

This partially reverts commit 836771a.

The repository infrastructure uses the "arduino/report-size-deltas" action to generate a report of the changes in memory
usage of the example sketches that would result from merging a pull request.

There are two use patterns for the "arduino/report-size-deltas" action:

* Run from a workflow triggered by a `schedule` event.
* Run from the same workflow as the "arduino/compile-sketches" action when triggered by a `pull_request` event.

The latter use pattern is only suitable for private repositories. The reason is that, when a pull request is submitted
from a fork, the permissions of the access token used by the "arduino/report-size-deltas" action are downgraded to
read-only in workflows triggered by a `pull_request` event, which means it is unable to make the report comment.

The reverted commit migrated the size deltas report infrastructure from the first use pattern to the second, which
caused the "Compile Examples" workflow runs to fail on pull requests submitted from forks:

Error: HTTPError: HTTP Error 403: Forbidden

For this reason, the infrastructure must be reverted back to using the first use pattern.

Author: per1234

.github/workflows/compile-examples.yml

@@ -12,12 +12,8 @@ on:
       - "examples/**"
       - "src/**"
 
-env:
-  # It's convenient to set variables for values used multiple times in the workflow.
-  SKETCHES_REPORTS_PATH: sketches-reports
-
 jobs:
-  compile:
+  build:
     runs-on: ubuntu-latest
 
     env:
@@ -35,6 +31,7 @@ jobs:
         - examples/ArduinoIoTCloud-Callbacks
         - examples/ArduinoIoTCloud-Schedule
         - examples/utility/ArduinoIoTCloud_Travis_CI
+      SKETCHES_REPORTS_PATH: sketches-reports
 
     strategy:
       fail-fast: false
@@ -295,28 +292,9 @@ jobs:
           google-key-file: ${{ secrets.GOOGLE_KEY_FILE }}
           spreadsheet-id: 1I6NZkpZpf8KugBkE92adB1Z3_b7ZepOpCdYTOigJpN4
 
-      # This step is needed to pass the size data to the report job.
       - name: Save memory usage change report as artifact
         if: github.event_name == 'pull_request'
         uses: actions/upload-artifact@v4
         with:
           name: sketches-report-${{ matrix.board.artifact-name-suffix }}
           path: ${{ env.SKETCHES_REPORTS_PATH }}
-
-  # When using a matrix to compile for multiple boards, it's necessary to use a separate job for the deltas report
-  report:
-    needs: compile # Wait for the compile job to finish to get the data for the report
-    if: github.event_name == 'pull_request' # Only run the job when the workflow is triggered by a pull request
-    runs-on: ubuntu-latest
-
-    steps:
-      # This step is needed to get the size data produced by the compile jobs
-      - name: Download sketches reports artifacts
-        uses: actions/download-artifact@v4
-        with:
-          # All workflow artifacts will be downloaded to this location.
-          path: ${{ env.SKETCHES_REPORTS_PATH }}
-
-      - uses: arduino/report-size-deltas@v1
-        with:
-          sketches-reports-source: ${{ env.SKETCHES_REPORTS_PATH }}

.github/workflows/report-size-deltas.yml

@@ -0,0 +1,14 @@
+on:
+  schedule:
+    - cron:  '*/5 * * * *'
+
+jobs:
+  report:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Comment size deltas reports to PRs
+        uses: arduino/report-size-deltas@v1
+        with:
+          # The name of the workflow artifact created by the "Compile Examples" workflow
+          sketches-reports-source: sketches-reports