sql: fix FK check bug in ALTER COLUMN TYPE

This commit fixes an implementation bug when checking that the table's
foreign keys didn't hold a reference to the altered column.

Fixes cockroachdb#71089.

Release justification: simple fix for blatant correctness bug

Release note (bug fix): fixes a bug which caused ALTER COLUMN TYPE
statements to fail when they shouldn't have.

pkg/sql/alter_column_type.go

@@ -205,9 +205,18 @@ func alterColumnTypeGeneralOld(
 	}
 
 	for _, fk := range tableDesc.AllActiveAndInactiveForeignKeys() {
-		for _, id := range append(fk.OriginColumnIDs, fk.ReferencedColumnIDs...) {
-			if col.ID == id {
-				return colWithConstraintNotSupportedErr
+		if fk.OriginTableID == tableDesc.GetID() {
+			for _, id := range fk.OriginColumnIDs {
+				if col.ID == id {
+					return colWithConstraintNotSupportedErr
+				}
+			}
+		}
+		if fk.ReferencedTableID == tableDesc.GetID() {
+			for _, id := range fk.ReferencedColumnIDs {
+				if col.ID == id {
+					return colWithConstraintNotSupportedErr
+				}
 			}
 		}
 	}