fix: Clean up nested ingest span logging

[QuentinMoss]

It seems handler trace was not closing scope properly when router was called async.

When sending a large number of requests to a successful endpoint I noticed that the span name was appending ingest. Notice the span names start appending ingest.

2023-07-01T03:12:14.875392Z TRACE ingest: soldr::db: insert_request
2023-07-01T03:12:14.875795Z DEBUG ingest: soldr::proxy: authority = example.wh.soldr.dev
2023-07-01T03:12:14.875827Z TRACE ingest: soldr::db: list_origins
2023-07-01T03:12:14.876075Z DEBUG soldr::proxy: origins = []
2023-07-01T03:12:14.876096Z TRACE soldr::proxy: no match found
2023-07-01T03:12:14.876121Z TRACE soldr::db: mark_complete
2023-07-01T03:12:14.884002Z DEBUG ingest:ingest: soldr: HttpRequest { method: "POST", uri: "/", headers: [("host", "example.wh.soldr.dev"), ("user-agent", "curl/7.81.0"), ("accept", "*/*"), ("content-length", "0"), ("content-type", "application/x-www-form-urlencoded")], body: Some([]) }
2023-07-01T03:12:14.884062Z TRACE ingest:ingest: soldr::db: insert_request
2023-07-01T03:12:14.884451Z DEBUG ingest:ingest: soldr::proxy: authority = example.wh.soldr.dev
2023-07-01T03:12:14.884477Z TRACE ingest:ingest: soldr::db: list_origins
2023-07-01T03:12:14.884635Z DEBUG soldr::proxy: origins = []
2023-07-01T03:12:14.884654Z TRACE soldr::proxy: no match found
2023-07-01T03:12:14.884671Z TRACE soldr::db: mark_complete
2023-07-01T03:12:14.892296Z DEBUG ingest:ingest:ingest: soldr: HttpRequest { method: "POST", uri: "/", headers: [("host", "example.wh.soldr.dev"), ("user-agent", "curl/7.81.0"), ("accept", "*/*"), ("content-length", "0"), ("content-type", "application/x-www-form-urlencoded")], body: Some([]) }