delete flaky pricing integration tests

[wpfleger96]

Summary

Fixes race condition causing test_pricing_cache_performance test to fail intermittently in CI with:

"No such file or directory (os error 2)"

Currently all 4 pricing integration tests share the same GOOSE_CACHE_DIR environment variable. Since environment variables are process-wide, when tests run in parallel (cargo test --jobs 2 in CI), one test can overwrite another's env var value. This creates a race window where Test A sets the env var, Test B overwrites it, then Test A reads Test B's (potentially deleted) path and fails. This is resulting in test failures on my unrelated PR

#3546 previously added TempDir isolation, but this only provided per-test directories and didn't prevent the tests from running in parallel and overwriting each other's environment variables.

To address this I added #[serial] attributes to all 4 pricing integration tests. This forces sequential execution of these tests only, while other tests continue running in parallel.

UPDATE: per feedback I'm just going to delete the flaky tests

Type of Change

• Feature
• Bug fix
• Refactor / Code quality
• Performance improvement
• Documentation
• Tests
• Security fix
• Build / Release
• Other (specify below)

Testing

I had trouble reproducing this locally, so I created a synthetic test (race_condition_demo.rs) locally that deliberately triggers the race condition:

  #[tokio::test]
  async fn race_test_1() {
      let temp_dir = TempDir::new().unwrap();
      std::env::set_var("GOOSE_CACHE_DIR", temp_dir.path());
      sleep(Duration::from_millis(50)).await;  // Widen race window

      let read_path = std::env::var("GOOSE_CACHE_DIR").unwrap();
      // Fails if Test 2 overwrote the env var
      assert!(Path::new(&read_path).exists());
  }

  #[tokio::test]
  async fn race_test_2() {
      sleep(Duration::from_millis(10)).await;  // Let Test 1 start first
      let temp_dir = TempDir::new().unwrap();
      std::env::set_var("GOOSE_CACHE_DIR", temp_dir.path());  // Overwrites Test 1!
      drop(temp_dir);  // Delete directory Test 1 might try to use
  }

Results:

• Without #[serial]: Test 1 panics with RACE CONDITION! Path doesn't exist: /tmp/.tmppTBwjl (Test 2's deleted path)
• With #[serial]: Both tests pass—Test 1 reads its own path correctly

Additional validation: Stress tested the fixed pricing tests with 10 consecutive runs using --jobs 4. All runs passed.