fix test increase timeout (#7022)
fix test increase timeout (#7022)

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**What this PR does / why we need it**:
increase timeout, fix test fail.
```
--- FAIL: TestInstanceFor (0.01s)
    downstreamer_test.go:205: 
        	Error Trace:	downstreamer_test.go:205
        	            				downstreamer_test.go:256
        	Error:      	lock couldn't be acquired
        	Test:       	TestInstanceFor
FAIL
```

**Which issue(s) this PR fixes**:
Fixes #<issue number>

**Special notes for your reviewer**:

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**Checklist**
- [ ] Documentation added
- [ ] Tests updated
- [ ] Is this an important fix or new feature? Add an entry in the `CHANGELOG.md`.
- [ ] Changes that require user attention or interaction to upgrade are documented in `docs/sources/upgrading/_index.md`
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