Update nom requirement from 7.0 to 8.0

Updates the requirements on [nom](https://github.com/rust-bakery/nom) to permit the latest version.
- [Changelog](https://github.com/rust-bakery/nom/blob/main/CHANGELOG.md)
- [Commits](rust-bakery/nom@7.0.0...8.0.0)

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

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

Author: dependabot[bot]

Cargo.toml

@@ -12,7 +12,7 @@ name = "matroska"
 path = "src/lib.rs"
 
 [dependencies]
-nom = "7.0"
+nom = "8.0"
 cookie-factory = "0.3"
 av-data = "0.4.1"
 av-format = "0.7"

tools/Cargo.toml

@@ -14,7 +14,7 @@ av-format = "0.7"
 circular = "0.3"
 log = "0.4"
 matroska = { path = ".." }
-nom = "7.0"
+nom = "8.0"
 pretty_env_logger = "0.5"
 err-derive = "0.3.0"
 time = { version = "0.3.20", features = ["formatting"] }