[test](p0) force replica = 1 in p0 regression tests (#45684)

### What problem does this PR solve?

Some tests in p0 does not set replica = 1, and will fail when BE number
is not enough.

This PR fixed this problem by set
`force_olap_table_replication_allocation` in p0 fe.conf

regression-test/pipeline/p0/conf/fe.conf

@@ -121,3 +121,5 @@ enable_advance_next_id = true
 # enable deadlock detection
 enable_deadlock_detection = true
 max_lock_hold_threshold_seconds = 10
+
+force_olap_table_replication_allocation=tag.location.default:1

regression-test/suites/partition_p0/dynamic_partition/test_dynamic_partition.groovy

@@ -15,6 +15,10 @@
 // specific language governing permissions and limitations
 // under the License.
 suite("test_dynamic_partition") {
+    def config_row = sql """ ADMIN SHOW FRONTEND CONFIG LIKE 'force_olap_table_replication_allocation'; """
+    String old_conf_value = config_row[0][1]
+    sql """ ADMIN SET FRONTEND CONFIG ("force_olap_table_replication_allocation" = ""); """
+
     // todo: test dynamic partition
     sql "drop table if exists dy_par"
     sql """
@@ -156,4 +160,7 @@ suite("test_dynamic_partition") {
         exception "errCode = 2,"
     }
     sql "drop table if exists dy_par_bad"
+
+    // restore force_olap_table_replication_allocation to old_value
+    sql """ ADMIN SET FRONTEND CONFIG ("force_olap_table_replication_allocation" = "${old_conf_value}"); """
 }