build(deps): Update bollard requirement from 0.16 to 0.20

Updates the requirements on [bollard](https://github.com/fussybeaver/bollard) to permit the latest version.
- [Release notes](https://github.com/fussybeaver/bollard/releases)
- [Changelog](https://github.com/fussybeaver/bollard/blob/master/RELEASE.md)
- [Commits](fussybeaver/bollard@v0.16.0...v0.20.2)

---
updated-dependencies:
- dependency-name: bollard
  dependency-version: 0.20.2
  dependency-type: direct:production
...

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

Author: dependabot[bot]

Cargo.toml

@@ -45,7 +45,7 @@ rusqlite = { version = "0.39", features = ["bundled"] }
 r2d2 = "0.8"
 
 # Docker
-bollard = "0.16"
+bollard = "0.20"
 
 # HTTP client (for LLM API)
 reqwest = { version = "0.12.24", default-features = false, features = ["json", "blocking", "rustls-tls"] }