fix(iroh): do not panic on blobs IO error #8739

Job	Run time
Checking fmt	10s
Checking docs	1m 12s
check_semver	4m 37s
cargo deny	28s
clippy_check	2m 56s
Cross Build Only (armv7-linux-androideabi)	1m 2s
Cross Test (i686-unknown-linux-gnu)	2m 32s
Minimal Supported Rust Version	2m 32s
Cross Build Only (aarch64-linux-android)	1m 1s
Cross Build Only (x86_64-unknown-freebsd)	1m 7s
Run network simulations/benchmarks	7m 54s
Cross Build Only (x86_64-unknown-netbsd)	1m 9s
Build wasm32	34s
CI Test Suite / Tests (windows-latest, stable, all, x86_64-pc-windows-msvc)	3m 57s
CI Test Suite / Tests (ubuntu-latest, stable, all)	2m 45s
CI Test Suite / Tests (windows-latest, stable, none, x86_64-pc-windows-msvc)	3m 53s
CI Test Suite / Tests (ubuntu-latest, stable, none)	2m 14s
CI Test Suite / Tests (windows-latest, stable, default, x86_64-pc-windows-msvc)	4m 12s
CI Test Suite / Tests (ubuntu-latest, stable, default)	2m 45s
CI Test Suite / Tests (macOS-arm-latest, stable, all)	3m 16s
CI Test Suite / Tests (macOS-arm-latest, stable, none)	2m 55s
CI Test Suite / Tests (macOS-arm-latest, stable, default)	2m 58s
	56m 9s

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