github actions: Remove obsolete exposed key

As the subject says, it's obsolete and the repo it was tied to
is long gone, but it's bad form to have it there.  Requestor is
actually passed in now so the value was not used in any case.

Signed-off-by: Greg Rose <[email protected]>

Author: gvrose8192

.github/workflows/process-git-request.rb

@@ -1,6 +1,6 @@
 require 'open3'
 
-requestors = { "gvrose8192" => "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" }
+requestors = { "gvrose8192" => "" }
 
 def file_prepend(file, str)
   new_contents = ""