chore: Publish nightly only when there were changes on branch (#8657)

## Summary

This PR now checks commits in the last 24hours, and only then it run the
nightly publish - I've tested it locally and it appeared to correctly
set the variables and work.

## Test plan

Author: patrycjakalinska

.github/workflows/check-branch-changes.yml

@@ -0,0 +1,33 @@
+name: Check branch changes
+on:
+  workflow_call:
+    inputs:
+      branch:
+        required: true
+        type: string
+    outputs:
+      has_changes:
+        value: ${{ jobs.check.outputs.has_changes }}
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    outputs:
+      has_changes: ${{ steps.commit_check.outputs.has_changes }}
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          ref: ${{ inputs.branch }}
+
+      - id: commit_check
+        run: |
+          COUNT=$(git log --oneline --since='24 hours ago' | wc -l)
+          echo "Found $COUNT commits in the last 24 hours on branch ${{ inputs.branch }}"
+
+          if [ "$COUNT" -gt 0 ]; then
+            echo "has_changes=true" >> $GITHUB_OUTPUT
+          else
+            echo "has_changes=false" >> $GITHUB_OUTPUT
+          fi

.github/workflows/npm-reanimated-publish-nightly.yml

@@ -11,15 +11,34 @@ permissions:
   id-token: write # For publishing on NPM using OIDC
 
 jobs:
-  npm-reanimated-4-publish-nightly:
+  check-v4-changes:
     if: github.repository == 'software-mansion/react-native-reanimated'
+    uses: ./.github/workflows/check-branch-changes.yml
+    with:
+      branch: main
+
+  npm-reanimated-4-publish-nightly:
+    needs: check-v4-changes
+    if: |
+      github.repository == 'software-mansion/react-native-reanimated' &&
+      needs.check-v4-changes.outputs.has_changes == 'true'
     uses: ./.github/workflows/npm-reanimated-package-build.yml
     with:
       option: --nightly
       publish_on_npm: true
 
-  npm-reanimated-3-publish-nightly:
+  check-v3-changes:
     if: github.repository == 'software-mansion/react-native-reanimated'
+    uses: ./.github/workflows/check-branch-changes.yml
+    with:
+      # Remember to update the branch on new minor releases.
+      branch: 3.19-stable
+
+  npm-reanimated-3-publish-nightly:
+    needs: check-v3-changes
+    if: |
+      github.repository == 'software-mansion/react-native-reanimated' &&
+      needs.check-v3-changes.outputs.has_changes == 'true'
     uses: ./.github/workflows/npm-reanimated-package-build.yml
     with:
       option: --nightly