Fix Dependabot for Cargo projects

I incorrectly assumed Dependabot can find the Cargo config files, however, the projects must be specified independently (see: dependabot/dependabot-core#2178).

Without this, Dependabot fails with the following error:

```
Dependabot couldn't find a Cargo.toml

Dependabot requires a Cargo.toml to evaluate your Rust dependencies. It had expected to find one at the path: /src/Cargo.toml.

If this isn't a Rust project, you may wish to disable updates for it in the .github/dependabot.yml config file in this repo.
```

See: https://github.com/adeira/universe/network/updates/91435760

.github/dependabot.yml

@@ -21,16 +21,25 @@ updates:
       interval: 'daily'
     labels:
       - 'dependencies'
-      - 'automerge' # see Kodiak `merge.automerge_label`
+      - 'automerge'
     open-pull-requests-limit: 10
 
   - package-ecosystem: 'cargo'
-    directory: '/src/'
+    directory: '/src/signedsource-rs/'
     schedule:
       interval: 'daily'
     labels:
       - 'dependencies'
-      - 'automerge' # see Kodiak `merge.automerge_label`
+      - 'automerge'
+    open-pull-requests-limit: 10
+
+  - package-ecosystem: 'cargo'
+    directory: '/src/ya-comiste-rust/'
+    schedule:
+      interval: 'daily'
+    labels:
+      - 'dependencies'
+      - 'automerge'
     open-pull-requests-limit: 10
 
   - package-ecosystem: 'docker'
@@ -39,5 +48,5 @@ updates:
       interval: 'daily'
     labels:
       - 'dependencies'
-      - 'automerge' # see Kodiak `merge.automerge_label`
+      - 'automerge'
     open-pull-requests-limit: 10