Remove host specification from pg_regress temporary instance (#10020)

It has no purpose and leads to TCP port collisions.

Author: akuzm

test/test-defs.cmake

@@ -75,8 +75,7 @@ file(
   NO_SOURCE_PERMISSIONS
   FILE_PERMISSIONS OWNER_READ OWNER_WRITE)
 
-set(PG_REGRESS_OPTS_BASE --host=${TEST_PGHOST}
-                         --dlpath=${PROJECT_BINARY_DIR}/src)
+set(PG_REGRESS_OPTS_BASE --dlpath=${PROJECT_BINARY_DIR}/src)
 
 set(PG_REGRESS_OPTS_EXTRA
     --create-role=${TEST_ROLE_SUPERUSER},${TEST_ROLE_DEFAULT_PERM_USER},${TEST_ROLE_DEFAULT_PERM_USER_2},${TEST_ROLE_1},${TEST_ROLE_2},${TEST_ROLE_3},${TEST_ROLE_4},${TEST_ROLE_READ_ONLY}
@@ -112,7 +111,8 @@ set(PG_REGRESS_OPTS_TEMP_INSTANCE_PGTEST
     --port=${TEST_PGPORT_TEMP_INSTANCE} --temp-instance=${TEST_CLUSTER}
     --temp-config=${TEST_OUTPUT_DIR}/pgtest.conf)
 
-set(PG_REGRESS_OPTS_LOCAL_INSTANCE --port=${TEST_PGPORT_LOCAL})
+set(PG_REGRESS_OPTS_LOCAL_INSTANCE --host=${TEST_PGHOST}
+                                   --port=${TEST_PGPORT_LOCAL})
 
 if(PG_REGRESS)
   set(PG_REGRESS_ENV