Add copilot[bot] to CLA allowlist

Co-authored-by: stesee <168659+stesee@users.noreply.github.com>

Author: Copilot

.github/workflows/cla.yml

@@ -22,7 +22,7 @@ jobs:
           path-to-document: "https://github.com/Codeuctivity/OpenXmlPowerTools/blob/main/cla.md" # e.g. a CLA or a DCO document
           # branch should not be protected
           branch: "cla"
-          allowlist: dependabot[bot],stesee
+          allowlist: dependabot[bot],stesee,copilot[bot]
 
           #below are the optional inputs - If the optional inputs are not given, then default values will be taken
           #remote-organization-name: enter the remote organization name where the signatures should be stored (Default is storing the signatures in the same repository)