Add Github workflow to check for Change log entry

.github/workflows/ensure-changelog-entry.yml

@@ -0,0 +1,72 @@
+name: Ensure change log entry
+on:
+  pull_request:
+    types: [opened, reopened, edited]
+
+jobs:
+  check:
+    # permissions:
+    #   issues: write
+    #   contents: read
+    runs-on: ubuntu-latest
+    steps:
+      - name: Find changelog entry
+        uses: actions/github-script@v7
+        with:
+          github-token: ${{secrets.GHA_PAT}}
+          script: |
+            // Is author a member of the DataDog Org.
+            // NOTE: https://docs.github.com/en/rest/orgs/members?apiVersion=2022-11-28#check-organization-membership-for-a-user
+            const creator = context.payload.sender.login
+            try {
+              response = await github.rest.orgs.checkMembershipForUser({
+                org: context.repo.owner,
+                username: creator
+              })
+
+              isMember = response.status == 204
+            } catch (e) {
+              console.log(e)
+
+              isMember = false
+            }
+
+            const username = !isMember ? "@DataDog/ruby-guild" : `@${ creator }`
+            const message = `:wave: Hey ${ username }, please fill "Change log entry" section in the pull request description.
+            If changes need to be present in [CHANGELOG.md](https://github.com/DataDog/dd-trace-rb/blob/master/CHANGELOG.md) you can state it this way
+
+            \`\`\`md
+            **Change log entry**
+
+            Yes. A brief summary to be placed into the CHANGELOG.md
+            \`\`\`
+            _(possible answers Yes/Yep/Yeah)_
+
+            Or you can opt out like that
+
+            \`\`\`md
+            **Change log entry**
+
+            None.
+            \`\`\`
+            _(possible answers No/Nope/None)_`
+
+            const regex = /\*\*Change log entry\*\*\s+(?:(?<answer_yes>yes|yep|yeah)(?:\.\s*(?<yes_message>.*))?|(?<answer_no>no|nope|none)\.?)\s*/mi
+            const entry = context.payload.pull_request.body.match(regex)
+
+            const isWriteComment =
+              !isMember
+                || null === entry
+                || (undefined === entry.groups.answer_yes && undefined === entry.groups.answer_no)
+                || (undefined !== entry.groups.answer_yes && undefined === entry.groups.yes_message)
+              ? true : false
+
+            if (isWriteComment) {
+              return
+              await github.rest.issues.createComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: ${{ github.event.pull_request.number }},
+                body: message
+              })
+            }