[Chore](nereids) Remove DropFunctionStmt

[codeDing18]

What problem does this PR solve?

Issue Number: close #xxx

Related PR: #xxx

Problem Summary:

Release note

None

Check List (For Author)

• Test

  • Regression test
  • Unit Test
  • Manual test (add detailed scripts or steps below)
  • No need to test or manual test. Explain why:
    • This is a refactor/code format and no logic has been changed.
    • Previous test can cover this change.
    • No code files have been changed.
    • Other reason

• Behavior changed:

  • No.
  • Yes.

• Does this need documentation?

  • No.
  • Yes.

Check List (For Reviewer who merge this PR)

• Confirm the release note
• Confirm test cases
• Confirm document
• Add branch pick label

[hello-stephen]

Thank you for your contribution to Apache Doris.
Don't know what should be done next? See How to process your PR.

Please clearly describe your PR:

1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
5. Which functions were optimized and what is the difference before and after the optimization?

[codeDing18]

run buildall

[doris-robot]

TPC-H: Total hot run time: 33936 ms

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/tpch-tools
Tpch sf100 test result on commit a22fbda57dd410c5dbbbf4f23533de51b0f2b68c, data reload: false

------ Round 1 ----------------------------------
q1	17556	5347	5342	5342
q2	1956	302	202	202
q3	10232	1388	726	726
q4	10235	994	533	533
q5	7528	2314	2308	2308
q6	181	170	131	131
q7	888	742	622	622
q8	9296	1231	1090	1090
q9	6747	5052	4994	4994
q10	6889	2343	2011	2011
q11	462	287	271	271
q12	344	367	231	231
q13	17758	3425	2998	2998
q14	226	239	231	231
q15	546	461	454	454
q16	417	425	385	385
q17	578	807	354	354
q18	7234	7081	7033	7033
q19	3150	983	555	555
q20	318	304	212	212
q21	3388	3137	2261	2261
q22	1079	1042	992	992
Total cold run time: 107008 ms
Total hot run time: 33936 ms

----- Round 2, with runtime_filter_mode=off -----
q1	5613	5417	5360	5360
q2	235	306	215	215
q3	2054	2548	2189	2189
q4	1319	1699	1391	1391
q5	4109	4540	4305	4305
q6	216	169	135	135
q7	2122	1933	1834	1834
q8	2447	2483	2381	2381
q9	7343	7529	7442	7442
q10	4477	3319	3014	3014
q11	573	504	485	485
q12	747	814	615	615
q13	3389	3659	3358	3358
q14	317	310	302	302
q15	501	477	469	469
q16	444	498	493	493
q17	1283	1447	1462	1447
q18	7852	7671	7576	7576
q19	9690	894	899	894
q20	3489	1933	1770	1770
q21	13710	4286	4241	4241
q22	1085	1044	966	966
Total cold run time: 73015 ms
Total hot run time: 50882 ms

[doris-robot]

TPC-DS: Total hot run time: 169584 ms

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/tpcds-tools
TPC-DS sf100 test result on commit a22fbda57dd410c5dbbbf4f23533de51b0f2b68c, data reload: false

============================================
query1	1002	388	425	388
query2	6552	1774	1725	1725
query3	6747	227	215	215
query4	27744	23581	22818	22818
query5	4340	639	523	523
query6	326	249	231	231
query7	4639	515	304	304
query8	299	240	249	240
query9	8607	2904	3006	2904
query10	479	345	299	299
query11	15703	15085	14786	14786
query12	185	133	128	128
query13	1665	572	409	409
query14	8656	5902	5888	5888
query15	217	191	170	170
query16	7127	661	465	465
query17	977	776	641	641
query18	2034	427	309	309
query19	229	201	187	187
query20	145	140	141	140
query21	214	166	106	106
query22	3874	3971	3838	3838
query23	34423	34223	34252	34223
query24	5242	2439	2465	2439
query25	488	496	438	438
query26	718	295	170	170
query27	2269	496	353	353
query28	3005	2317	2323	2317
query29	669	620	485	485
query30	299	235	195	195
query31	872	778	739	739
query32	86	76	72	72
query33	541	406	407	406
query34	792	828	513	513
query35	809	853	757	757
query36	1015	1026	932	932
query37	136	118	96	96
query38	3968	3919	3886	3886
query39	1448	1364	1378	1364
query40	235	143	132	132
query41	61	61	55	55
query42	141	133	127	127
query43	508	525	492	492
query44	1395	879	871	871
query45	202	187	183	183
query46	933	1068	674	674
query47	1799	1801	1706	1706
query48	401	444	319	319
query49	663	521	424	424
query50	665	669	423	423
query51	4140	4219	4130	4130
query52	127	130	114	114
query53	251	287	214	214
query54	654	648	570	570
query55	91	87	88	87
query56	348	356	360	356
query57	1221	1200	1127	1127
query58	329	337	334	334
query59	2598	2679	2496	2496
query60	391	393	376	376
query61	123	121	120	120
query62	765	761	641	641
query63	251	217	223	217
query64	2358	1138	783	783
query65	4282	4111	4108	4108
query66	1068	463	330	330
query67	query68	17403	853	966	853
query69	1033	277	281	277
query70	1294	1116	1055	1055
query71	724	318	323	318
query72	9146	2269	2148	2148
query73	3495	685	352	352
query74	9159	8966	8784	8784
query75	7596	3133	2692	2692
query76	8788	1231	829	829
query77	1138	399	322	322
query78	9392	11350	9201	9201
query79	15460	663	596	596
query80	1904	589	536	536
query81	570	261	225	225
query82	560	154	119	119
query83	479	293	273	273
query84	292	99	79	79
query85	1057	378	328	328
query86	377	307	326	307
query87	4259	4195	4088	4088
query88	5613	2238	2271	2238
query89	502	378	328	328
query90	2605	236	238	236
query91	159	142	193	142
query92	93	73	68	68
query93	6594	977	673	673
query94	1168	392	288	288
query95	435	337	335	335
query96	499	600	289	289
query97	2720	2722	2604	2604
query98	250	223	245	223
query99	1447	1383	1270	1270
Total cold run time: 300752 ms
Total hot run time: 169584 ms

[doris-robot]

ClickBench: Total hot run time: 32.99 s

machine: 'aliyun_ecs.c7a.8xlarge_32C64G'
scripts: https://github.com/apache/doris/tree/master/tools/clickbench-tools
ClickBench test result on commit a22fbda57dd410c5dbbbf4f23533de51b0f2b68c, data reload: false

query1	0.04	0.04	0.03
query2	0.08	0.04	0.04
query3	0.25	0.07	0.07
query4	1.65	0.11	0.11
query5	0.43	0.41	0.42
query6	1.16	0.64	0.64
query7	0.03	0.01	0.02
query8	0.05	0.04	0.04
query9	0.58	0.48	0.47
query10	0.52	0.52	0.52
query11	0.15	0.11	0.10
query12	0.14	0.10	0.10
query13	0.65	0.64	0.65
query14	0.99	1.10	1.12
query15	0.92	0.87	0.89
query16	0.37	0.39	0.38
query17	1.03	1.04	1.05
query18	0.23	0.20	0.20
query19	1.99	1.86	1.99
query20	0.02	0.01	0.01
query21	15.37	0.83	0.55
query22	0.78	1.30	0.85
query23	14.74	1.16	0.65
query24	7.08	1.18	0.46
query25	0.53	0.18	0.13
query26	0.54	0.15	0.14
query27	0.06	0.06	0.06
query28	9.38	0.88	0.46
query29	12.73	3.86	3.35
query30	3.00	2.98	2.95
query31	2.82	0.58	0.40
query32	3.25	0.58	0.50
query33	3.02	3.18	3.25
query34	15.96	5.34	4.91
query35	4.87	4.91	4.96
query36	0.70	0.53	0.49
query37	0.11	0.08	0.07
query38	0.06	0.05	0.05
query39	0.03	0.02	0.03
query40	0.18	0.15	0.13
query41	0.07	0.03	0.03
query42	0.04	0.03	0.03
query43	0.05	0.03	0.04
Total cold run time: 106.65 s
Total hot run time: 32.99 s

[hello-stephen]

FE UT Coverage Report

Increment line coverage 0.00% (0/1) 🎉
Increment coverage report
Complete coverage report

[github-actions]

PR approved by at least one committer and no changes requested.

[github-actions]

PR approved by anyone and no changes requested.

[dataroaring]

LGTM