fix: dont test thread backend in jinad

[jacobowitz]

Thread backend for a runtime worker does not work well with containers. Dont test it in jinad

[github-actions]

Latency summary

Current PR yields:

• 😶 index QPS at 1171, delta to last 2 avg.: +0%
• 😶 query QPS at 20, delta to last 2 avg.: -5%
• 😶 dam extend QPS at 35254, delta to last 2 avg.: +7%
• 😶 avg flow time within 1.5265 seconds, delta to last 2 avg.: -4%
• 🐢🐢 import jina within 0.4084 seconds, delta to last 2 avg.: -8%

Breakdown

Version	Index QPS	Query QPS	DAM Extend QPS	Avg Flow Time (s)	Import Time (s)
current	1171	20	35254	1.5265	0.4084
2.6.4	1144	20	31770	1.5918	0.4839
2.6.3	1199	21	33967	1.5934	0.4128

Backed by latency-tracking. Further commits will update this comment.