[OpenAPI] some errors on the spec

Describe the bug
The OpenAPI spec have several errors

Steps to reproduce (if applicable)

1. curl the content of /openapi.json
2. dump it into https://editor.swagger.io/

Expected behavior
No errors

Configuration:

1. Output of quickwit --version => v0.8.0

Output

Errors

 
Structural error at paths./api/v1/_elastic.get.responses
should define at least one response
Jump to line 16
Structural error at paths./api/v1/config.get.responses
should define at least one response
Jump to line 36
Semantic error at paths./api/v1/indexes.get.parameters.1.name
Path parameter "index_id_patterns" must have the corresponding {index_id_patterns} segment in the "/api/v1/indexes" path
Jump to line 54
Semantic error at paths./api/v1/indexes/{index_id}.delete.responses.200.content.application/json.schema.items.$ref
$refs must reference a valid location in the document
Jump to line 121
Semantic error at paths./api/v1/indexes/{index_id}/splits.get.responses.200.content.application/json.schema.$ref
$refs must reference a valid location in the document
Jump to line 337
Semantic error at paths./api/v1/templates/{template_id}
Declared path parameter "template_id" needs to be defined as a path parameter at either the path or operation level
Jump to line 400
Structural error at paths./api/v1/version.get.responses
should define at least one response
Jump to line 438
Semantic error at paths./api/v1/{otel-traces-index-id}/jaeger/api/services.get.responses.200.content.application/json.schema.$ref
$refs must reference a valid location in the document
Jump to line 787
Semantic error at paths./api/v1/{otel-traces-index-id}/jaeger/api/services/{service}/operations.get.responses.200.content.application/json.schema.$ref
$refs must reference a valid location in the document
Jump to line 812
Semantic error at paths./api/v1/{otel-traces-index-id}/jaeger/api/traces.get.responses.200.content.application/json.schema.$ref
$refs must reference a valid location in the document
Jump to line 890
Semantic error at paths./api/v1/{otel-traces-index-id}/jaeger/api/traces/{id}.get.responses.200.content.application/json.schema.$ref
$refs must reference a valid location in the document
Jump to line 915
Semantic error at paths./debugging.get.responses.200.content.application/json.schema.$ref
$refs must reference a valid location in the document
Jump to line 933

Start by fetching /openapi.json from Quickwit v0.8.0 and loading it in the Swagger Editor to reproduce the listed structural and semantic errors. Trace the OpenAPI generation for the affected endpoints, including /api/v1/_elastic, /api/v1/config, index and Jaeger routes, and /debugging. Done means the generated specification validates without any of the reported errors.