impl(librarian.yaml): add streaming package dependencies config

librarian.yaml

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 language: rust
-version: v0.38.1-0.20260819164204-f3a328be2b9d
+version: v0.38.1-0.20260820171450-084470b21056
 repo: googleapis/google-cloud-rust
 sources:
   conformance:
@@ -108,6 +108,15 @@ default:
       - name: google-shopping-type
         package: google-shopping-type
         source: google.shopping.type
+      - name: http
+        package: http
+        used_if: streaming
+      - name: prost
+        package: prost
+        used_if: streaming
+      - name: prost-types
+        package: prost-types
+        used_if: streaming
       - name: serde
         package: serde
         force_used: true

src/generated/showcase/Cargo.toml

@@ -42,12 +42,6 @@ default-rustls-provider = ["gaxi/_default-rustls-provider"]
 all-features = true
 
 [dependencies]
-prost.workspace                    = true
-prost-types.workspace              = true
-futures.workspace                  = true
-http.workspace                     = true
-tokio.workspace                    = true
-tokio-stream.workspace             = true
 async-trait.workspace              = true
 bytes.workspace                    = true
 gaxi                               = { workspace = true, features = ["_internal-grpc-client", "_internal-http-client"] }
@@ -57,6 +51,9 @@ google-cloud-location.workspace    = true
 google-cloud-longrunning.workspace = true
 google-cloud-lro.workspace         = true
 google-cloud-rpc.workspace         = true
+http.workspace                     = true
+prost-types.workspace              = true
+prost.workspace                    = true
 serde.workspace                    = true
 serde_json.workspace               = true
 serde_with.workspace               = true

src/generated/showcase/src/model.rs

@@ -28,6 +28,9 @@ extern crate google_cloud_location;
 extern crate google_cloud_longrunning;
 extern crate google_cloud_lro;
 extern crate google_cloud_rpc;
+extern crate http;
+extern crate prost;
+extern crate prost_types;
 extern crate serde;
 extern crate serde_json;
 extern crate serde_with;