Get rid of `release_date` environment variable - now we use `release_date` input of GHA instead

.github/workflows/build-firmware.yaml

@@ -19,7 +19,7 @@ jobs:
       id: set-variables
       run: |
         if [ "${{github.event_name}}" = "schedule" ]; then
-          echo "release_date=$(date +'%Y-%m-%d')" >> $GITHUB_ENV
+          echo "release_date=$(date +'%Y-%m-%d')" >> $GITHUB_OUTPUT
         fi
         if [ "${{github.event_name}}" == "push" -o "${{github.event_name}}" == "schedule" -o "${{github.event_name}}" == "workflow_dispatch" ] && [ "${{github.ref}}" == "refs/heads/master" -o "${{github.ref}}" == "refs/heads/main" ]; then
           echo 'upload=bundles' >> $GITHUB_OUTPUT
@@ -32,6 +32,7 @@ jobs:
 
     - uses: ./ext/rusefi/.github/workflows/custom-board-build
       with:
+        release_date: ${{steps.set-variables.outputs.release_date}}
         artifacts: bin srec hex list map elf bundle autoupdate
         uploads: ini ${{steps.set-variables.outputs.upload}}
         push: ${{steps.set-variables.outputs.push}}