TemplateTypeHelper: prevent unnecessary work

[staabm]

most time consuming user of TypeTraverser::map() is TemplateTypeHelper::resolveTemplateTypes:

while TypeTraverser::map() is the most time consuming method-call in shopware (and also in phpstan-src reference benchmark):

after this PR TypeTraverser::map() no longer is in the top 8 of slow calls, while beeing in top 2 before.

---

before this PR:

➜  phpstan-src git:(2.1.x) ✗ hyperfine 'php bin/phpstan analyse src/Analyser/ src/Rules/ -v --debug' -i --runs=3 --warmup=1
Benchmark 1: php bin/phpstan analyse src/Analyser/ src/Rules/ -v --debug
  Time (mean ± σ):     26.391 s ±  0.413 s    [User: 25.598 s, System: 0.780 s]
  Range (min … max):   25.959 s … 26.783 s    3 runs
 
  Warning: Ignoring non-zero exit code.

after this PR:

➜  phpstan-src git:(early-ret) ✗ hyperfine 'php bin/phpstan analyse src/Analyser/ src/Rules/ -v --debug' -i --runs=3 --warmup=1
Benchmark 1: php bin/phpstan analyse src/Analyser/ src/Rules/ -v --debug
  Time (mean ± σ):     25.841 s ±  0.046 s    [User: 25.103 s, System: 0.729 s]
  Range (min … max):   25.788 s … 25.872 s    3 runs
 
  Warning: Ignoring non-zero exit code.

[ondrejmirtes]

Thank you!