Tests fail with Os { code: 24, kind: Uncategorized, message: "Too many open files" }

[leplatrem]

Running cargo test --all-features on Mac OS fails with:

failures:

---- client::tests::test_sync_uses_specified_expected_parameter stdout ----
thread 'client::tests::test_sync_uses_specified_expected_parameter' panicked at 'Failed building the Runtime: Os { code: 24, kind: Uncategorized, message: "Too many open files" }', src/client.rs:1347:36
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

---- client::tests::test_sync_uses_x5u_from_metadata_to_verify_signatures stdout ----
thread '<unnamed>' panicked at 'Cannot build local tokio runtime: Os { code: 24, kind: Uncategorized, message: "Too many open files" }', /Users/mathieu/.cargo/registry/src/github.com-1ecc6299db9ec823/httpmock-0.6.6/src/api/server.rs:285:14
thread 'client::tests::test_sync_uses_x5u_from_metadata_to_verify_signatures' panicked at 'Cannot get server address: RecvError(())', /Users/mathieu/.cargo/registry/src/github.com-1ecc6299db9ec823/httpmock-0.6.6/src/api/server.rs:290:37

---- client::tests::test_sync_wraps_signature_errors stdout ----
thread 'client::tests::test_sync_wraps_signature_errors' panicked at 'Cannot build HTTP client: Error { kind: ClientInitialization, context: None, source: Some(Os { code: 24, kind: Uncategorized, message: "Too many open files" }), source_type: Some("std::io::error::Error"), local_addr: None, remote_addr: None }', /Users/mathieu/.cargo/registry/src/github.com-1ecc6299db9ec823/httpmock-0.6.6/src/api/adapter/mod.rs:133:14


failures:
    client::tests::test_sync_uses_specified_expected_parameter
    client::tests::test_sync_uses_x5u_from_metadata_to_verify_signatures
    client::tests::test_sync_wraps_signature_errors