Data race on `workspaceACLDisabled` in tests

[Emyrk]

Failure: https://github.com/coder/coder/actions/runs/21517957455/job/62001120065?pr=21773

Logs: https://productionresultssa17.blob.core.windows.net/actions-results/054aa58a-aa5f-40d2-b88b-27e3e0576002/workflow-job-run-d8b3e948-8438-5b95-89f2-02ba57b74115/logs/job/job-logs.txt?rsct=text%2Fplain&se=2026-01-30T14%3A36%3A56Z&sig=96%2Fc6uEoUZxNP7M6YTNMn4d6JI2JJ3T8hm5V2s5M7C8%3D&ske=2026-01-30T15%3A53%3A14Z&skoid=ca7593d4-ee42-46cd-af88-8b886a2f84eb&sks=b&skt=2026-01-30T11%3A53%3A14Z&sktid=398a6654-997b-47e9-b12b-9515b896b4de&skv=2025-11-05&sp=r&spr=https&sr=b&st=2026-01-30T14%3A26%3A51Z&sv=2025-11-05

https://github.com/coder/coder/blob/9062e10fe3a84b82f2d0c359353488e132a045a9/coderd/rbac/object.go#L240-L255

SetWorkspaceACLDisabled should probably be mutex protected?

[flake-investigator]

New occurrence on main:

• CI run: https://github.com/coder/coder/actions/runs/21524384366
• Failing job: https://github.com/coder/coder/actions/runs/21524384366/job/62024077590 (test-go-race-pg)
• Commit: 37aecda165d8697766fd42399416afce6ad41dcb (Danielle Maywood)

Race detector output:

WARNING: DATA RACE
Write at 0x00000c85c71f by goroutine 12588:
  github.com/coder/coder/v2/coderd/rbac.SetWorkspaceACLDisabled()
    /home/runner/work/coder/coder/coderd/rbac/object.go:247
  github.com/coder/coder/v2/coderd_test.TestUpdateWorkspaceACL.func4.1()
    /home/runner/work/coder/coder/coderd/workspaces_test.go:5199

Previous read at 0x00000c85c71f by goroutine 4433:
  github.com/coder/coder/v2/coderd/database.WorkspaceTable.RBACObject()
    /home/runner/work/coder/coder/coderd/database/modelmethods.go:438
  github.com/coder/coder/v2/coderd.(*agentConnectionMonitor).monitor()
    /home/runner/work/coder/coder/coderd/workspaceagentsrpc.go:452

Tests marked as failed with race detector:

• TestAuditLogDescription -> testing.go:1617: race detected during execution of test
• TestWorkspaceAgent_Startup -> testing.go:1617: race detected during execution of test
• TestWorkspaceDormant -> testing.go:1617: race detected during execution of test

Full job summary ended with: DONE 13876 tests, 66 skipped, 17 failures in 434.717s.