No diagnostic for Obsoleted pctor-declared props when record body doesn't contain an attribute

[xparadoxical]

Version Used:
'4.14.0-ci (<developer build>)'. Language version: preview. (sharplab main 11 Jan 2025)
'4.12.0-3.24572.7 (dfa7fc6b)'. Language version: 13.0.

Steps to Reproduce:
(sharplab)

new R(true).B.Dump();
record R([property: Obsolete("a", true)] bool B);

Add anything with an attribute to the record to get a diagnostic (sharplab)

Diagnostic Id:
CS0619: 'R.B' is obsolete: 'a'

Expected Behavior:
Produces a diagnostic.
Actual Behavior:
Doesn't, unless the record contains anything with an attribute.