H-3519: `harpc`: rework the `Connection` type #11335

Job	Run time
setup	20s
Integration (@rust/authorization)	2m 5s
Integration (@rust/graph-benches)	1m 49s
Publish	0s
Build (@apps/hash-ai-worker-ts)	13m 3s
Integration (@rust/graph-http-tests)	6m 4s
Build (@apps/hash-api)	11m 4s
Integration (@rust/graph-integration)	4m 36s
Build (@apps/hash-graph)	8m 10s
Integration (@tests/hash-backend-integration)	7m 6s
Build (@apps/hash-integration-worker)	12m 7s
Integration (@tests/hash-backend-load)	6m 17s
Integration (@tests/hash-playwright)	12m 32s
Unit (@apps/hash-ai-worker-ts)	1m 43s
Unit (@apps/hash-api)	1m 33s
Unit (@blockprotocol/type-system)	44s
Unit (@blockprotocol/type-system-rs)	1m 45s
Unit (@local/hash-backend-utils)	1m 34s
Unit (@local/hash-graph-sdk)	1m 0s
Unit (@local/hash-isomorphic-utils)	1m 16s
Unit (@local/hash-subgraph)	56s
Unit (@rust/antsi)	53s
Unit (@rust/chonky)	59s
Unit (@rust/deer)	59s
Unit (@rust/error-stack)	1m 31s
Unit (@rust/graph)	1m 47s
Unit (@rust/graph-api)	1m 19s
Unit (@rust/graph-types)	1m 5s
Unit (@rust/harpc-net)	1m 26s
Unit (@rust/harpc-types)	1m 22s
Unit (@rust/harpc-wire-protocol)	50s
Unit (@rust/hql-cst)	1m 22s
Unit (@rust/hql-diagnostics)	56s
Unit (@rust/hql-span)	1m 16s
Unit (@rust/hql-syntax-jexpr)	1m 13s
Unit (@rust/query-builder-derive)	1m 18s
Unit (@rust/sarif)	1m 23s
Unit (@rust/temporal-versioning)	1m 30s
Unit (@rust/validation)	49s
Tests passed	5s
	1h 57m 47s

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