Disable spotless ratcheting of Pkl sources (#1295)

This causes spotless to _always_ format Pkl files, instead of only
formatting them if there's a diff between the file and what's in main.

This means that formatting changes in pkl-formatter will be propagated
to the standard library.

buildSrc/src/main/kotlin/pklSpotlessFormat.gradle.kts

@@ -27,6 +27,9 @@ spotless {
       rootProject.file("buildSrc/src/main/resources/license-header.line-comment.txt"),
       "/// ",
     )
+    // disable ratcheting for Pkl sources
+    // make any change to pkl-formatter reformat the stdlib
+    ratchetFrom = null
   }
 }