Bump toml from 0.8.23 to 0.9.7 in /backend (#104)

Bumps [toml](https://github.com/toml-rs/toml) from 0.8.23 to 0.9.7.
- [Commits](toml-rs/toml@toml-v0.8.23...toml-v0.9.7)

---
updated-dependencies:
- dependency-name: toml
  dependency-version: 0.9.7
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

backend/Cargo.lock

@@ -17,7 +17,7 @@
     "raw_value",
   ] }
   tokio = { version = "1.47.1", features = [ "macros", "rt-multi-thread" ] }
-  toml = { version = "0.8.20" }
+  toml = { version = "0.9.7" }
   tower-http = { version = "0.6", features = [ "cors" ] }
   tracing = { version = "0.1" }
   tracing-subscriber = { version = "0.3.20", features = [ "env-filter" ] }