Update cla-check.yml to be caseinsensitive

.github/workflows/cla-check.yml

@@ -14,7 +14,7 @@ jobs:
  if: ${{ (github.event.pull_request.user.login != github.repository_owner) }}
  steps:
  - run: |
- if ! curl -s https://raw.githubusercontent.com/Jermolene/TiddlyWiki5/tiddlywiki-com/licenses/cla-individual.md | grep -o "@$USER,"; then
+ if ! curl -s https://raw.githubusercontent.com/Jermolene/TiddlyWiki5/tiddlywiki-com/licenses/cla-individual.md | grep -io "@$USER,"; then
  echo "CLA not signed"
  gh pr comment "$NUMBER" -b "@$USER It appears that this is your first contribution to the project, welcome.