[ci] Ignore unsigned bundletool.jar content (#9139)

Fix sign check verify for the redistributed bundletool.jar,
which has been failing with:

    bundletool.jardir\com\sun\jna\win32-x86\jnidispatch.dll : Certificate : SignTool Error: No signature found.
    bundletool.jardir\com\sun\jna\win32-x86-64\jnidispatch.dll : Certificate : SignTool Error: No signature found.

build-tools/create-packs/SignVerifyIgnore.txt

@@ -1,2 +1,3 @@
 **\*.xml,ignore unsigned xml
 **\cab*.cab.cab,ignore unsigned .cab
+**\com\sun\jna\win32-*\jnidispatch.dll, ignore external bundletool.jar content