Remove redundant declaration for XidInMVCCSnapshot

Commit b7eda3e0e3 moves XidINMVCCSnapshot into snapmgr.{c,h},
however, it forgets the declaration of XidINMVCCSnapshot in
heapam.h.

Attached removes the redundant declaration in heapam.h.

-- 
Regrads,
Japin Li.
ChengDu WenWu Information Technology Co.,Ltd.

From 16f4bd33d7886c872319393dfebb5dd570b750ab Mon Sep 17 00:00:00 2001
From: Japin Li <japinli@hotmail.com>
Date: Wed, 9 Nov 2022 18:40:11 +0800
Subject: [PATCH v1 1/1] Remove redundant declaration for XidInMVCCSnapshot

---
 src/include/access/heapam.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index 9dab35551e..5b07875740 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -213,7 +213,6 @@ extern HTSV_Result HeapTupleSatisfiesVacuumHorizon(HeapTuple htup, Buffer buffer
 extern void HeapTupleSetHintBits(HeapTupleHeader tuple, Buffer buffer,
                                  uint16 infomask, TransactionId xid);
 extern bool HeapTupleHeaderIsOnlyLocked(HeapTupleHeader tuple);
-extern bool XidInMVCCSnapshot(TransactionId xid, Snapshot snapshot);
 extern bool HeapTupleIsSurelyDead(HeapTuple htup,
                                   struct GlobalVisState *vistest);
 
-- 
2.25.1