[BUG][Rust] Invalid Rust code generated

https://api.inaturalist.org/v1/swagger.json

error[E0599]: the method `join` exists for struct `Vec<i32>`, but its trait bounds were not satisfied
    --> src/apis/identifications_api.rs:1260:105
     |
1260 |     let local_var_uri_str = format!("{}/identifications/{id}", local_var_configuration.base_path, id=id.join(",").as_ref());
     |                                                                                                         ^^^^ method cannot be called on `Vec<i32>` due to unsatisfied trait bounds
     |
     = note: the following trait bounds were not satisfied:
             `[i32]: Join<_>`

error[E0599]: the method `join` exists for struct `Vec<i32>`, but its trait bounds were not satisfied
    --> src/apis/observations_api.rs:2394:102
     |
2394 |     let local_var_uri_str = format!("{}/observations/{id}", local_var_configuration.base_path, id=id.join(",").as_ref());
     |                                                                                                      ^^^^ method cannot be called on `Vec<i32>` due to unsatisfied trait bounds
     |
     = note: the following trait bounds were not satisfied:
             `[i32]: Join<_>`

warning: variable does not need to be mutable
  --> src/apis/photos_api.rs:57:9
   |
57 |     let mut local_var_form = reqwest::multipart::Form::new();
   |         ----^^^^^^^^^^^^^^
   |         |
   |         help: remove this `mut`
   |
   = note: `#[warn(unused_mut)]` on by default

error[E0283]: type annotations needed
   --> src/apis/places_api.rs:126:106
    |
126 |     let local_var_uri_str = format!("{}/places/{id}", local_var_configuration.base_path, id=id.join(",").as_ref());
    |                                                                                             -------------^^^^^^--
    |                                                                                             |            |
    |                                                                                             |            cannot infer type for type parameter `T` declared on the trait `AsRef`
    |                                                                                             this method call resolves to `&T`
    |
    = note: multiple `impl`s satisfying `std::string::String: AsRef<_>` found in the following crates: `alloc`, `std`:
            - impl AsRef<OsStr> for std::string::String;
            - impl AsRef<Path> for std::string::String;
            - impl AsRef<[u8]> for std::string::String;
            - impl AsRef<str> for std::string::String;

error[E0283]: type annotations needed
   --> src/apis/projects_api.rs:520:108
    |
520 |     let local_var_uri_str = format!("{}/projects/{id}", local_var_configuration.base_path, id=id.join(",").as_ref());
    |                                                                                               -------------^^^^^^--
    |                                                                                               |            |
    |                                                                                               |            cannot infer type for type parameter `T` declared on the trait `AsRef`
    |                                                                                               this method call resolves to `&T`
    |
    = note: multiple `impl`s satisfying `std::string::String: AsRef<_>` found in the following crates: `alloc`, `std`:
            - impl AsRef<OsStr> for std::string::String;
            - impl AsRef<Path> for std::string::String;
            - impl AsRef<[u8]> for std::string::String;
            - impl AsRef<str> for std::string::String;

error[E0599]: the method `join` exists for struct `Vec<i32>`, but its trait bounds were not satisfied
   --> src/apis/taxa_api.rs:274:94
    |
274 |     let local_var_uri_str = format!("{}/taxa/{id}", local_var_configuration.base_path, id=id.join(",").as_ref());
    |                                                                                              ^^^^ method cannot be called on `Vec<i32>` due to unsatisfied trait bounds
    |
    = note: the following trait bounds were not satisfied:
            `[i32]: Join<_>`

The problem seems to be this line:

https://github.com/OpenAPITools/openapi-generator/blob/21f649e0873f29571b9bb9b69c7a8e962e3954d0/modules/openapi-generator/src/main/resources/rust/reqwest/api.mustache#L99

Start with the Rust template at modules/openapi-generator/src/main/resources/rust/reqwest/api.mustache, especially line 99, then generate a client from the linked Swagger document. Compare the affected identifications, observations, places, projects, and taxa API calls with the compiler errors. Done means the generated Rust client compiles without these join and type-inference errors.