Streamlines the vendored `mongodb` instrumentation to use Sentry's span
APIs instead of the OpenTelemetry tracing APIs, following the
redis/pg/mongoose precedent.

- Replace `tracer.startSpan` with `startInactiveSpan`, the
  `trace.getSpan(context.active())` + `requireParentSpan` guard with a
  `getActiveSpan()` check, `SpanStatusCode.ERROR` with `SPAN_STATUS_ERROR`,
  and the `context.with(...)`/`context.bind(...)` propagation with
  `withActiveSpan` (result-handler re-activation and the pool `checkOut`
  rebind). Drop `recordException` and the `_diag` logger.
- Drop the OTel connection-usage metrics: the SDK wires up no
  `MeterProvider`, so `this.meter` is the no-op meter and every `add` was
  dead. Also removes the session and connect patches that existed only to
  feed those metrics (they create no spans, so span output is unchanged).
- Drop the `SemconvStability` dual-emission and keep the OLD semconv
  attributes only (the STABLE path was env-gated behind
  `OTEL_SEMCONV_STABILITY_OPT_IN` and never enabled by the SDK).
- Remove config the SDK never passes (`responseHook`, the configurable
  `dbStatementSerializer`, `requireParentSpan`); move the always-on
  statement serializer into the vendored code and bake the
  `auto.db.otel.mongo` origin into the span attributes instead of an
  `index.ts` responseHook.
- Drop the blanket eslint-disable, type the module, and split the helpers
  (`utils.ts`) and wrap factories (`patches.ts`) out of the class to keep
  each vendored file within `max-lines`.

Removes the config-passing `Mongo` unit test (its serializer logic is
covered end-to-end by the integration suite) and extends the real suite
with an error path: a server-rejected query asserts `status:
'internal_error'` with the origin and `db.statement` preserved.