Micro optimize LazyInternalScopeFactory

[staabm]

getParameter() is showing up in perf profiles

before this PR

➜  phpstan-src git:(2.1.x) hyperfine 'php bin/phpstan analyze src/Analyser/NodeScopeResolver.php --debug # Old' -i
Benchmark 1: php bin/phpstan analyze src/Analyser/NodeScopeResolver.php --debug # Old
  Time (mean ± σ):      7.266 s ±  0.020 s    [User: 7.079 s, System: 0.183 s]
  Range (min … max):    7.230 s …  7.292 s    10 runs

after this PR

➜  phpstan-src git:(2.1.x) ✗ hyperfine 'php bin/phpstan analyze src/Analyser/NodeScopeResolver.php --debug # New' -i
Benchmark 1: php bin/phpstan analyze src/Analyser/NodeScopeResolver.php --debug # New
  Time (mean ± σ):      7.124 s ±  0.018 s    [User: 6.935 s, System: 0.184 s]
  Range (min … max):    7.085 s …  7.156 s    10 runs

[ondrejmirtes]

Thank you.