fix(coderd): use WaitSuperLong in TestReinitializeAgent (#22593)

Fixes coder/internal#642

We recently fixed Windows specific flakes for this test and reenabled
it. It then failed intermittently due to context deadline expiration.
The temporary path created on Windows contained invalid characters. This
resulted in a silent startup script failure on Windows. The test then
fruitlessly waited until context expiration. The test now uses a valid
path on Windows.

testutil/goleak.go

@@ -18,4 +18,7 @@ var GoleakOptions []goleak.Option = []goleak.Option{
 	goleak.IgnoreTopFunction("gopkg.in/natefinch/lumberjack%2ev2.(*Logger).mill.func1"),
 	// The pq library appears to leave around a goroutine after Close().
 	goleak.IgnoreTopFunction("github.com/lib/pq.NewDialListener"),
+	// The go-winio library starts a process-level I/O completion port
+	// goroutine via sync.Once that is never terminated.
+	goleak.IgnoreAnyFunction("github.com/Microsoft/go-winio.ioCompletionProcessor"),
 }