feat!: new quic-rpc, simlified generics, bump MSRV to 1.76 (#2268)

## Description

Adapts iroh for n0-computer/quic-rpc#76

Wit this change, a quic client is
`pub type QuicIroh = Iroh<QuinnConnection<RpcService>>`
instead of
`pub type QuicIroh = Iroh<QuinnConnection<ProviderRequest,
ProviderResponse>>`

## Breaking Changes
* Increased mimimal supported rust version (MSRV) from 1.75 to 1.76
* The generics of the iroh clients changed: Instead of taking
`ProviderRequest, ProviderResponse` as generics, they now take
`RpcService`

## Notes & open questions

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## Change checklist

- [x] Self-review.
- [x] Documentation updates if relevant.
- [x] Tests if relevant.
- [x] All breaking changes documented.

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Co-authored-by: dignifiedquire <[email protected]>

Author: Frando