mononoke: lower CAT verifier-identity-mismatch log to debug

Summary:
This warning is producing log spew in production server logs whenever a CAT token's verifier identity does not match the configured one (a common occurrence: any CAT meant for a different verifier on the same Mononoke host shows up here). The skip is expected behavior — the token simply does not apply to this verifier and we fall back to other auth — so a per-token warn is too loud. Drop it to debug, matching the level of the other "no header present" / "extracted identity" log lines in this module. The other warn-level logs in this file (deserialize failure, verification error, verification not successful) stay at warn because they indicate a malformed or invalid token that callers may want to investigate.

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overriding_review_checks_triggers_an_audit_and_retroactive_review
Oncall Short Name: source_control

Differential Revision: D103855548

fbshipit-source-id: 7a6fd6dcb57fc36d284915cffcaf545b6d477af7

Author: mzr

eden/mononoke/common/cats/src/lib.rs

@@ -111,7 +111,7 @@ fn extract_identity_from_token(
     if tdata.verifierIdentity.id_type != verifier_identity.id_type
         || tdata.verifierIdentity.id_data != verifier_identity.id_data
     {
-        warn!(
+        debug!(
             "CAT token skipped: verifier identity mismatch (token has {}:{}, expected {}:{})",
             tdata.verifierIdentity.id_type,
             tdata.verifierIdentity.id_data,