fix(mgmt_api) : role deletion/update fails when role key contains a slash (#9958)

# Which Problems Are Solved

- Role deletion or update API returns `404 Not Found` when the role key
contains a slash (`/`), even if URL encoded.
- This breaks management of hierarchical role keys like
`admin/org/reader`.

# How the Problems Are Solved

- Updated the HTTP binding in the protobuf definition for the affected
endpoints to use `{role_key=**}` instead of `{role_key}`.
- This change enables proper decoding and handling of slashes in role
keys as a single path variable.

# Additional Changes
None

# Additional Context
- Closes https://github.com/zitadel/zitadel/issues/9948

Co-authored-by: Masum Patel <patelmasum98@gmail.com>
Co-authored-by: Tim Möhlmann <tim+github@zitadel.com>

proto/zitadel/management.proto

@@ -3101,7 +3101,7 @@ service ManagementService {
 
     rpc UpdateProjectRole(UpdateProjectRoleRequest) returns (UpdateProjectRoleResponse) {
         option (google.api.http) = {
-            put: "/projects/{project_id}/roles/{role_key}"
+            put: "/projects/{project_id}/roles/{role_key=**}"
             body: "*"
         };
 
@@ -3127,7 +3127,7 @@ service ManagementService {
 
     rpc RemoveProjectRole(RemoveProjectRoleRequest) returns (RemoveProjectRoleResponse) {
         option (google.api.http) = {
-            delete: "/projects/{project_id}/roles/{role_key}"
+            delete: "/projects/{project_id}/roles/{role_key=**}"
         };
 
         option (zitadel.v1.auth_option) = {