Minimize hand-edit to generated 38052 catalog file

Keep only the functional -Wpedantic addition in the generated catalog
regression; drop the hand-written prose so a future regeneration has
less to reconcile.

Author: expipiplus1

docs/generated/tests/design/cross-cutting/diagnostics-catalog/38052-vertex-shader-missing-sv-position.slang

@@ -11,8 +11,7 @@
 //META: catalog_name=vertex-shader-missing-sv-position
 //META: warning=Auto-generated. May drift from source. Do not edit by hand.
 
-// A vertex shader with no SV_Position output triggers W38052. This warning is in the `pedantic`
-// group (off by default), so it is opt-in via -Wpedantic.
+// A vertex shader with no SV_Position output triggers W38052.
 
 //DIAGNOSTIC_TEST:SIMPLE(diag=CHECK,non-exhaustive):-Wpedantic -target hlsl -entry main -stage vertex -profile sm_5_0