fix: fix 2 cargo warnings

[rikhuijzer]

This fixes three warnings that cargo test produced.

Motivation and Context

Locally and in CI the following warnings were visible:

$ cargo test --all-features
warning: /home/runner/work/rust-sdk/rust-sdk/examples/rig-integration/Cargo.toml: unused manifest key: dependencies.rmcp.no-default-features
warning: /home/runner/work/rust-sdk/rust-sdk/crates/rmcp/Cargo.toml: unused manifest key: dependencies.rmcp-macros.version
warning: /home/runner/work/rust-sdk/rust-sdk/examples/wasi/Cargo.toml: version requirement `0.14.2+wasi-0.2.4` for dependency `wasi` includes semver metadata which will be ignored, removing the metadata is recommended to avoid confusion

How Has This Been Tested?

I re-ran all tests and also manually "tested" (built) rig-integration via

$ cd examples/righ-integration

$ cargo build

For rig-integration I verified that setting default-features = false will not be able to build the project, so that's why I removed it. Note that default-features = false is interpreted by Cargo while the setting no-default-features = true was ignored.

Breaking Changes

No

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context

[rikhuijzer]

This was ignored by cargo because it should be default-features = false.

[rikhuijzer]

This was also ignored by Cargo according to

 warning: /home/runner/work/rust-sdk/rust-sdk/examples/wasi/Cargo.toml: version requirement `0.14.2+wasi-0.2.4` for dependency `wasi` includes semver metadata which will be ignored, removing the metadata is recommended to avoid confusion

[4t145]

LGTM, we can fix the rest one warning latter. Thank you for PR.