deps/refactor: port to iroh 0.91 (#47)

## Description

Ports iroh-docs to iroh 0.91 and from quic-rpc to irpc.

TODOs / Missing features vs iroh-docs 0.35:

- [ ] `Doc::export_file` and `Doc::import_file` are missing. Would need
some more work to port them, I didn't get around to that yet. But it's
not super critical, as you can import via iroh-blobs and then use
Doc::set_hash.
- [ ] Document all the API changes (this is quite a bit of work - best
way likely to compare the docs for old and new version)
- [ ] Maybe: Convert errors to snafu. This is still using anyhow and
thiserror. It is quite some work, not sure about it yet.

Status for everything else
- All APIs converted
- All tests pass

## Breaking Changes

Quite a few. TODO: Document.

<!-- Optional, if there are any breaking changes document them,
including how to migrate older code. -->

## Notes & open questions

<!-- Any notes, remarks or open questions you have to make about the PR.
-->

## Change checklist

- [ ] Self-review.
- [ ] Documentation updates following the [style
guide](https://rust-lang.github.io/rfcs/1574-more-api-documentation-conventions.html#appendix-a-full-conventions-text),
if relevant.
- [ ] Tests if relevant.
- [ ] All breaking changes documented.

Author: Frando

.github/workflows/ci.yaml

@@ -16,7 +16,7 @@ env:
   RUST_BACKTRACE: 1
   RUSTFLAGS: -Dwarnings
   RUSTDOCFLAGS: -Dwarnings
-  MSRV: "1.81"
+  MSRV: "1.85"
   SCCACHE_CACHE_SIZE: "50G"
   IROH_FORCE_STAGING_RELAYS: "1"
 
@@ -205,7 +205,7 @@ jobs:
     - uses: actions/checkout@v4
     - uses: dtolnay/rust-toolchain@master
       with:
-        toolchain: nightly-2024-11-30
+        toolchain: nightly-2025-05-01
     - name: Install sccache
       uses: mozilla-actions/sccache-action@v0.0.9
 

.github/workflows/docs.yaml

@@ -32,7 +32,7 @@ jobs:
     - uses: actions/checkout@v4
     - uses: dtolnay/rust-toolchain@master
       with:
-        toolchain: nightly-2024-11-30
+        toolchain: nightly-2025-05-01
     - name: Install sccache
       uses: mozilla-actions/sccache-action@v0.0.9