Update apache/skywalking-eyes digest to 9a20e0c

Author: oxide-renovate[bot]

.github/workflows/licence-check.yml

@@ -12,4 +12,4 @@ jobs:
     steps:
     - uses: actions/checkout@master
     - name: Check License Header
-      uses: apache/skywalking-eyes/header@4f4281f13ebf854ebf514c1d5c3ea6797ae7e234
+      uses: apache/skywalking-eyes/header@9a20e0c14c8dead3404be1b92c78d4ad048c1144