Add CLA bot GitHub action (#3995)

Add CLA bot GitHub action

fix format

Co-authored-by: BenoitZugmeyer <benoit.zugmeyer@datadoghq.com>
Co-authored-by: ara.pulido <ara.pulido@datadoghq.com>

Author: arapulido

.github/workflows/cla.yml

@@ -0,0 +1,51 @@
+name: 'CLA Assistant'
+on:
+  issue_comment:
+    types: [created]
+  pull_request_target:
+    types: [opened, closed, synchronize]
+  merge_group:
+    types: [checks_requested]
+
+permissions:
+  contents: read
+  pull-requests: write
+  id-token: write # Needed to federate tokens.
+  actions: write
+
+jobs:
+  CLAAssistant:
+    runs-on: ubuntu-latest
+    steps:
+      - name: CLA already verified on PR
+        if: github.event_name == 'merge_group'
+        run: echo "CLA verification not needed for merge queue - already checked on PR"
+
+      - uses: DataDog/dd-octo-sts-action@08f2144903ced3254a3dafec2592563409ba2aa0 # v1.0.1
+        if: github.event_name != 'merge_group'
+        id: octo-sts
+        with:
+          scope: DataDog/cla-signatures
+          policy: self.write-signatures-browser-sdk
+
+      - name: 'CLA Assistant'
+        if: github.event_name != 'merge_group' && ((github.event.comment.body == 'recheck' || github.event.comment.body == 'I have read the CLA Document and I hereby sign the CLA') || github.event_name == 'pull_request_target')
+        uses: contributor-assistant/github-action@ca4a40a7d1004f18d9960b404b97e5f30a505a08 # v2.6.1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          PERSONAL_ACCESS_TOKEN: ${{ steps.octo-sts.outputs.token }}
+        with:
+          path-to-signatures: 'browser-sdk.json'
+          path-to-document: 'https://gist.github.com/bits-bot/55bdc97a4fdad52d97feb4d6c3d1d618' # Datadog CLA Document
+          branch: 'browser-sdk'
+          remote-repository-name: cla-signatures
+          remote-organization-name: DataDog
+
+          # the followings are the optional inputs - If the optional inputs are not given, then default values will be taken
+          #allowlist: user1,bot*
+          #create-file-commit-message: 'For example: Creating file for storing CLA Signatures'
+          #signed-commit-message: 'For example: $contributorName has signed the CLA in $owner/$repo#$pullRequestNo'
+          #custom-notsigned-prcomment: 'pull request comment with Introductory message to ask new contributors to sign'
+          #custom-pr-sign-comment: 'The signature to be committed in order to sign the CLA'
+          #custom-allsigned-prcomment: 'pull request comment when all contributors has signed, defaults to **CLA Assistant Lite bot** All Contributors have signed the CLA.'
+          #lock-pullrequest-aftermerge: false - if you don't want this bot to automatically lock the pull request after merging (default - true)