fix(iroh-blobs): Demote `warn!` to `trace!` logs #10185

Job	Run time
Cross Build Only (x86_64-unknown-freebsd)	1m 12s
Android Build Only (aarch64-linux-android)	1m 23s
Android Build Only (armv7-linux-androideabi)	1m 25s
Checking docs	1m 25s
Checking fmt	12s
check_semver	4m 51s
Cross Test (i686-unknown-linux-gnu)	3m 32s
Build wasm32	27s
cargo deny	28s
Checking typos	4s
clippy_check	2m 41s
codespell	5s
Docker Test	2m 3s
Minimal Supported Rust Version	1m 48s
Run network simulations/benchmarks	8m 33s
CI Test Suite / Tests (ubuntu-latest, stable, all)	3m 54s
CI Test Suite / Tests (ubuntu-latest, stable, none)	2m 53s
CI Test Suite / Tests (windows-latest, stable, all, x86_64-pc-windows-msvc)	4m 10s
CI Test Suite / Tests (windows-latest, stable, none, x86_64-pc-windows-msvc)	4m 9s
CI Test Suite / Tests (ubuntu-latest, stable, default)	3m 6s
CI Test Suite / Tests (windows-latest, stable, default, x86_64-pc-windows-msvc)	4m 13s
CI Test Suite / Tests (macOS-arm-latest, stable, all)	4m 13s
CI Test Suite / Tests (macOS-arm-latest, stable, none)	3m 46s
CI Test Suite / Tests (macOS-arm-latest, stable, default)	3m 38s
	1h 4m 11s

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