fix(router): skip sessions for stateless routes

[xHeaven]

Fixes #2065.

Note: this makes it so sessions won't run for unmatched/404 routes, because the matcher now short-circuits before the session middleware. Not sure if this is acceptable.

[github-actions]

Benchmark Results

Comparison of fix/middleware-prio against 3.x (08cc44693058b3ffb4a33e4b4d6590da4a9a3356).

Open to see the benchmark results

Benchmark	Set	Mem. Peak	Time	Variability
QueryExecutionBench(benchFetchAll)	-	4.349mb 0.00%	46.860μs +5.30%	±2.90% +122.87%
GenericRouterBench(benchDispatch)	Dynamic route	5.139mb +0.04%	69.626μs -5.93%	±0.59% -65.21%
GenericRouterBench(benchDispatch)	Dynamic short	5.139mb +0.04%	69.470μs -5.90%	±0.43% +51.59%
GenericRouterBench(benchDispatchWithoutMiddleware)	Dynamic route	5.138mb +0.04%	58.979μs -6.66%	±1.17% +56.31%
GenericRouterBench(benchDispatchWithoutMiddleware)	Dynamic short	5.138mb +0.04%	58.835μs -6.26%	±1.17% +373.54%

_{Generated by phpbench against commit 00b28ec}

[brendt]

so sessions won't run for unmatched/404 routes

I can't think of any problem this would cause, so let's merge and see 👍