[VL] Do not unload shared libraries

[zhztheplayer]

Unloading could be problematical when user pre-installs the shared libraries on executor's OS. Removing it in this patch.

[github-actions]

Thanks for opening a pull request!

Could you open an issue for this pull request on Github Issues?

https://github.com/oap-project/gluten/issues

Then could you also rename commit message and pull request title in the following format?

[GLUTEN-${ISSUES_ID}][COMPONENT]feat/fix: ${detailed message}

See also:

• Other pull requests

[zhouyuan]

👍

[GlutenPerfBot]

===== Performance report for TPCH SF2000 with Velox backend, for reference only ====

query	log/native_1762_time.csv	log/native_master_10_09_2023_65a72b1c3_time.csv	difference	percentage
q1	42.93	42.87	-0.063	99.85%
q2	24.43	24.57	0.148	100.61%
q3	35.74	37.52	1.781	104.98%
q4	42.74	41.91	-0.827	98.07%
q5	70.32	69.35	-0.968	98.62%
q6	6.26	6.58	0.317	105.07%
q7	86.31	86.66	0.352	100.41%
q8	81.20	81.22	0.016	100.02%
q9	116.43	117.00	0.563	100.48%
q10	47.27	46.63	-0.641	98.64%
q11	19.26	19.22	-0.044	99.77%
q12	25.02	25.03	0.009	100.04%
q13	49.47	49.58	0.112	100.23%
q14	17.30	13.15	-4.145	76.04%
q15	31.85	29.50	-2.353	92.61%
q16	15.39	16.05	0.661	104.29%
q17	120.46	122.83	2.373	101.97%
q18	161.61	164.00	2.392	101.48%
q19	12.10	12.01	-0.086	99.29%
q20	29.11	26.66	-2.455	91.57%
q21	238.86	236.75	-2.111	99.12%
q22	15.46	15.77	0.311	102.01%
total	1289.53	1284.87	-4.656	99.64%