Update rubato requirement from 0.14 to 0.15

Updates the requirements on [rubato](https://github.com/HEnquist/rubato) to permit the latest version.
- [Release notes](https://github.com/HEnquist/rubato/releases)
- [Commits](HEnquist/rubato@v0.14.0...v0.15.0)

---
updated-dependencies:
- dependency-name: rubato
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Cargo.toml

@@ -37,7 +37,7 @@ llq = "0.1.1"
 log = "0.4"
 num-complex = "0.4"
 realfft = "3.3"
-rubato = "0.14"
+rubato = "0.15"
 smallvec = "1.11"
 symphonia = { version = "0.5", default-features = false }
 vecmath = "1.0"