update: bump config from 0.14.1 to 0.15.11

Bumps [config](https://github.com/rust-cli/config-rs) from 0.14.1 to 0.15.11.
- [Changelog](https://github.com/rust-cli/config-rs/blob/main/CHANGELOG.md)
- [Commits](rust-cli/config-rs@v0.14.1...v0.15.11)

---
updated-dependencies:
- dependency-name: config
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

Cargo.lock

@@ -75,7 +75,7 @@ c2pa-crypto = { path = "../internal/crypto", version = "0.7.0" }
 c2pa-status-tracker = { path = "../internal/status-tracker", version = "0.6.0" }
 chrono = { version = "0.4.39", default-features = false, features = ["serde"] }
 ciborium = "0.2.2"
-config = { version = "0.14.0", default-features = false, features = [
+config = { version = "0.15.11", default-features = false, features = [
     "json",
     "json5",
     "toml",