workaround and fixes for MPL and copywrite bot (#18775)

scripts/copywrite-exceptions.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+
+# Used as a stopgap for copywrite bot in MPL-licensed subdirs, detects BUSL licensed
+# headers and deletes them, then runs the copywrite bot to utilize local subdir config
+# to inject correct headers.
+
+find . -type f -name '*.go' | while read line; do
+  if grep "SPDX-License-Identifier: BUSL-1.1" $line; then
+    sed -i '/SPDX-License-Identifier: BUSL-1.1/d' $line
+    sed -i '/Copyright (c) HashiCorp, Inc./d' $line
+  fi
+done
+
+copywrite headers --plan