Optimize config resolution for non-matching targets in --exact runs

[franciszekjob]

Towards #3899

Introduced changes

Skip config resolution for non-matching targets when --exact flag is used. This change is helpful for test run code lens in LS, since they use --exact.

With --workspace flag

Before

➜  cairo-contracts git:(main) ✗ hyperfine --runs 5 "snforge test openzeppelin_token::tests::erc721::test_erc721::test_transfer_from_nonexistent --exact --workspace"                 
Benchmark 1: snforge test openzeppelin_token::tests::erc721::test_erc721::test_transfer_from_nonexistent --exact --workspace
  Time (mean ± σ):     38.935 s ±  7.293 s    [User: 97.577 s, System: 19.230 s]
  Range (min … max):   30.666 s … 48.018 s    5 runs

After

➜  cairo-contracts git:(main) ✗ hyperfine --runs 5 "/Users/franciszekjob/Projects/SWM/starknet-foundry/target/release/snforge test openzeppelin_token::tests::erc721::test_erc721::test_transfer_from_nonexistent --exact --workspace"                 
Benchmark 1: /Users/franciszekjob/Projects/SWM/starknet-foundry/target/release/snforge test openzeppelin_token::tests::erc721::test_erc721::test_transfer_from_nonexistent --exact --workspace
  Time (mean ± σ):     29.249 s ±  2.614 s    [User: 22.787 s, System: 14.182 s]
  Range (min … max):   25.940 s … 32.706 s    5 runs

With --package flag

Before

➜  cairo-contracts git:(main) ✗ hyperfine --runs 5 "snforge test openzeppelin_token::tests::erc721::test_erc721::test_transfer_from_nonexistent --exact --package openzeppelin_token" 
Benchmark 1: snforge test openzeppelin_token::tests::erc721::test_erc721::test_transfer_from_nonexistent --exact --package openzeppelin_token
  Time (mean ± σ):     16.125 s ±  1.337 s    [User: 38.437 s, System: 6.164 s]
  Range (min … max):   14.457 s … 17.824 s    5 runs

After

➜  cairo-contracts git:(main) ✗ hyperfine --runs 5 "/Users/franciszekjob/Projects/SWM/starknet-foundry/target/release/snforge test openzeppelin_token::tests::erc721::test_erc721::test_transfer_from_nonexistent --exact --package openzeppelin_token"
Benchmark 1: /Users/franciszekjob/Projects/SWM/starknet-foundry/target/release/snforge test openzeppelin_token::tests::erc721::test_erc721::test_transfer_from_nonexistent --exact --package openzeppelin_token
  Time (mean ± σ):     11.330 s ±  1.318 s    [User: 7.184 s, System: 4.180 s]
  Range (min … max):    9.696 s … 13.110 s    5 runs

(Benches done in comparison with snforge nightly-2026-04-22)

Checklist

• Linked relevant issue
• Updated relevant documentation
• Added relevant tests
• Performed self-review of the code
• Added changes to CHANGELOG.md

[franciszekjob]

note: Compilation was moved below so it happens only if there are tests to be run from a test target.

[franciszekjob]

note: We can extend it later so the optimization will work with test name filter too. However, this will be related with the number of filtered out tests, which is displayed. For --exact we simply display other filtered out while for matching name filter, we actually count them.