Inner closures captured `sourceKitLSPServer` implicitly. The outer
`Task` already captures it weakly, making it a `var` in scope; inner
@Sendable closures that capture this `var` implicitly trigger the
`SendableClosureCaptures` diagnostic on compiler configurations
without `ImmutableWeakCaptures`.
Add explicit `[weak sourceKitLSPServer]` to each inner closure so the
capture binds cleanly to a fresh weak local.
Rintaro Ishizaki
f0231e287f