[#28522] YSQL: fix 'TestToastFunction#testBuildRelcacheInitFileMemoryUsage'

Summary:
`TestToastFunction` has hard-coded constants (8 MB) that it expects the
CacheMemoryContext size to fall below. Since D45540 adds a new view
this limit gets crossed.

This revision increases the limit to account for, D45540
Jira: DB-18212

Test Plan:
./yb_build.sh --java-test 'org.yb.pgsql.TestToastFunction'

Reviewers: myang, kfranz

Reviewed By: myang, kfranz

Differential Revision: https://phorge.dev.yugabyte.com/D46580

Author: IshanChhangani

java/yb-pgsql/src/test/java/org/yb/pgsql/TestToastFunction.java

@@ -61,6 +61,6 @@ public void testAdHocMemoryUsage() throws Exception {
   public void testBuildRelcacheInitFileMemoryUsage() throws Exception {
     setEnableToastFlag(true);
     CacheMemoryContextTracker cxt = buildRelcacheInitFileMemoryUsage();
-    cxt.assertMemoryUsageLessThan(8 * MB);
+    cxt.assertMemoryUsageLessThan(9 * MB);
   }
 }