Revert "adding workspace_build resource (#4636)" (#4742)

This reverts commit 145faf4400.

coderd/database/migrations/000064_add_audit_enums.down.sql

@@ -1,2 +0,0 @@
--- It's not possible to drop enum values from enum types, so the UP has "IF NOT
--- EXISTS".

coderd/database/migrations/000064_add_audit_enums.up.sql

@@ -1,4 +0,0 @@
-ALTER TYPE audit_action ADD VALUE IF NOT EXISTS 'start';
-ALTER TYPE audit_action ADD VALUE IF NOT EXISTS 'stop';
-
-ALTER TYPE resource_type ADD VALUE IF NOT EXISTS 'workspace_build';