Pin lambda_runtime to 0.7.1

rust-runtime/aws-smithy-http-server-python/Cargo.toml

@@ -23,6 +23,11 @@ futures = "0.3"
 http = "0.2"
 hyper = { version = "0.14.20", features = ["server", "http1", "http2", "tcp", "stream"] }
 lambda_http = { version = "0.7.1" }
+# There is a breaking change in `lambda_runtime` between `0.7.0` and `0.7.1`,
+# and `lambda_http` depends on `0.7` which by default resolves to `0.7.1` but in our CI
+# we are running `minimal-versions` which downgrades `lambda_runtime` to `0.7.0` and fails to compile
+# because of the breaking change. Here we are forcing it to use `lambda_runtime = 0.7.1`.
+lambda_runtime = { version = "0.7.1" }
 num_cpus = "1.13.1"
 parking_lot = "0.12.1"
 pin-project-lite = "0.2"