remove cc @dev-experience-support in testcase as well
Created by: burmudar
In #37152 we removed cc: @dev-experience-support
this updates the test for that change as well
Test plan
Executed the unit tests
go test -v -run TestBranchEventSummary ./dev/buildchecker
=== RUN TestBranchEventSummary
=== RUN TestBranchEventSummary/unlocked
=== RUN TestBranchEventSummary/locked
--- PASS: TestBranchEventSummary (0.33s)
--- PASS: TestBranchEventSummary/unlocked (0.33s)
--- PASS: TestBranchEventSummary/locked (0.00s)
PASS
ok github.com/sourcegraph/sourcegraph/dev/buildchecker (cached)```
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