sp_BlitzCache: scope NumberOfPlans UPDATE to current SPID

##BlitzCacheProcs is a global temp table; with concurrent sp_BlitzCache
runs it can hold rows for multiple SPIDs. The UPDATE that sets
NumberOfPlans / NumberOfDistinctPlans didn't have a SPID predicate, so it
would touch other sessions' rows too (and cause unnecessary blocking).
Add the standard @@spid filter, matching the two UPDATEs immediately
above it at lines 3041 and 3107.

Addresses review feedback on BrentOzarULTD#3940.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: BrentOzar

sp_BlitzCache.sql

@@ -3181,6 +3181,7 @@ FROM
 ) AS x
 WHERE ##BlitzCacheProcs.QueryHash = x.QueryHash
 AND   ##BlitzCacheProcs.DatabaseName = x.DatabaseName
+AND   ##BlitzCacheProcs.SPID = @@SPID
 OPTION (RECOMPILE) ;
 
 -- query level checks