Remove external PR greeter bot comment

It is folded into the PR template.

Author: clonker

.github/workflows/welcome-external-pr.yml

@@ -27,15 +27,4 @@ jobs:
           echo "Commenting in a newly submitted or reopened external PR: $PR"
           if [[ $DRY_RUN == 'false' ]]; then
             gh pr edit "$PR" --add-label "external contribution :star:"
-            comment_body=(
-              "Thank you for your contribution to the Solidity compiler! A team member will follow up shortly."
-              "\n\n"
-              "If you haven't read our [contributing guidelines](https://docs.soliditylang.org/en/latest/contributing.html) and our "
-              "[review checklist](https://github.com/argotorg/solidity/blob/develop/ReviewChecklist.md) before, "
-              "please do it now, this makes the reviewing process and accepting your contribution smoother."
-              "\n\n"
-              "If you have any questions or need our help, feel free to post them in the PR or talk to us directly on the "
-              "[#solidity-dev](https://matrix.to/#/#ethereum_solidity-dev:gitter.im) channel on Matrix."
-            )
-            gh pr comment $PR --body "$(IFS='' ; echo -e "${comment_body[*]}")"
           fi