deps: Update rodio requirement from 0.19 to 0.21

[dependabot]

Updates the requirements on rodio to permit the latest version.

Changelog

Sourced from rodio's changelog.

Version [0.21.1] (2025-07-14)

Changed

• Upgrade cpal to v0.16.
• Update dependencies.

Fixed

• Fix clippy warnings with Source::white and Source::pink functions.

Version [0.21.0] (2025-07-12)

Added

• Added Source::amplify_decibel() method to control volume by decibels.
• Added Source::amplify_normalized() method to perceptually modify volume.
• Adds a function to write a Source to a wav file, enable the wav_output feature and see output_to_wav.
• Output audio stream buffer size can now be adjusted.
• Sources for directly generating square waves, triangle waves, square waves, and sawtooths have been added.
• An interface for defining SignalGenerator patterns with an fn, see GeneratorFunction.
• Minimal builds without cpal audio output are now supported. See README.md for instructions. (#349)
• Added Sample::is_zero() method for checking zero samples.
• Added DecoderBuilder for improved configuration.
• Added Pausable::is_paused() method for checking if source is paused.
• Using Decoder::TryFrom for File now automatically wraps in BufReader and sets byte_len. TryFrom<Cursor<T>> and TryFrom<BufReader> are also supported.
• Added Source::distortion() method to control distortion effect by gain and threshold.
• Added OutputStream::config() method to access an OutputStream's OutputStreamConfig once an OutputStream has been built.
• Added OutputStreamConfig::channel_count(), OutputStreamConfig::sample_rate(), OutputStreamConfig::buffer_size() and OutputStreamConfig::sample_format() getters to access an OutputStreamConfig's channel count, sample rate, buffer size and sample format values.
• Added Source::limit() method for limiting the maximum amplitude of a source.
• Added more noise generators: WhiteGaussian, WhiteTriangular, Blue, Brownian, Violet, and Velvet.

Changed

• Breaking: OutputStreamBuilder should now be used to initialize an audio output stream.
• Breaking: OutputStreamHandle removed, use OutputStream and OutputStream::mixer() instead.
• Breaking: DynamicMixerController renamed to Mixer, DynamicMixer renamed to MixerSource.
• Breaking: Sink::try_new renamed to connect_new and does not return error anymore. Sink::new_idle was renamed to new.
• Breaking: symphonia::SeekError has a new variant AccurateSeekNotSupported and variants Retrying and Refining have been removed. Catching this error may allow a caller to retry in coarse seek mode.
• Breaking: symphonia::SeekError has a new variant RandomAccessNotSupported. This error usually means that you are trying to seek backward without is_seekable or byte_len set: use Decoder::try_from or DecoderBuilder for that.
• Breaking: In the Source trait, the method current_frame_len() was renamed to current_span_len().
• Breaking: Decoder now outputs f32 samples.

... (truncated)

Commits

• 7f10fcc release 0.21.1
• c5cf3d8 Merge branch 'master' of github.com:RustAudio/rodio
• ca5fb55 add dep update to release procedure
• 7d5b34b Merge pull request #767 from RustAudio/fix/0.21-cleanup
• 741611c docs: fix Markdown link syntax in UPGRADE.md
• b66b87a ci: run clippy with all features
• 385db77 fix(clippy): deprecated attribute must contain minor version
• 3ff2ac9 dep: bump hound, rstest, and update crates (#766)
• d30bfd0 Merge pull request #765 from RustAudio/feat/cpal-0.16
• e705ee9 docs: update cpal to v0.16 in changelog
• Additional commits viewable in compare view

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

---

Dependabot commands and options

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot recreate will recreate this PR, overwriting any edits that have been made to it
• @dependabot merge will merge this PR after your CI passes on it
• @dependabot squash and merge will squash and merge this PR after your CI passes on it
• @dependabot cancel merge will cancel a previously requested merge and block automerging
• @dependabot reopen will reopen this PR if it is closed
• @dependabot close will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
• @dependabot show <dependency name> ignore conditions will show all of the ignore conditions of the specified dependency
• @dependabot ignore this major version will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this minor version will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this dependency will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)

[dependabot]

Labels

The following labels could not be found: dependencies, rust. Please create them before Dependabot can add them to a pull request.

Please fix the above issues or remove invalid values from dependabot.yml.