Snowbridge Rococo deployment updates (#2792)

- Includes the introduction of the `fast-runtime` feature, which cleans
up our features
- Updates beacon client fork versions config to Sepolia's versions
- Cleanup of AgentIdOf

---------

Co-authored-by: Ron <yrong1997@gmail.com>
Co-authored-by: claravanstaden <Cats 4 life!>

bridges/snowbridge/parachain/pallets/ethereum-beacon-client/Cargo.toml

@@ -77,7 +77,6 @@ std = [
 	'frame-benchmarking/std',
 ]
 runtime-benchmarks = [
-	"beacon-spec-mainnet",
 	"frame-benchmarking/runtime-benchmarks",
 	"frame-support/runtime-benchmarks",
 	"frame-system/runtime-benchmarks",
@@ -92,4 +91,5 @@ try-runtime = [
 	"pallet-timestamp?/try-runtime",
 	"sp-runtime/try-runtime",
 ]
-beacon-spec-mainnet = []
+beacon-spec-minimal = []
+fast-runtime = ["beacon-spec-minimal"]