Update iai-callgrind requirement from 0.14.0 to 0.15.1

Updates the requirements on [iai-callgrind](https://github.com/iai-callgrind/iai-callgrind) to permit the latest version.
- [Release notes](https://github.com/iai-callgrind/iai-callgrind/releases)
- [Changelog](https://github.com/iai-callgrind/iai-callgrind/blob/main/CHANGELOG.md)
- [Commits](iai-callgrind/iai-callgrind@v0.14.0...v0.15.1)

---
updated-dependencies:
- dependency-name: iai-callgrind
  dependency-version: 0.15.1
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

lofty/Cargo.toml

@@ -39,7 +39,7 @@ rusty-fork = "0.3.0"
 structopt = { version = "0.3.26", default-features = false }
 tempfile  = "3.15.0"
 test-log = "0.2.16"
-iai-callgrind = "0.14.0"
+iai-callgrind = "0.15.1"
 
 [lints]
 workspace = true