[browser] Library with RuntimeIdentifier=browser-wasm shouldn't be SelfContained

[maraf]

• Re-enable Wasm.Build.Tests.WasmTemplateTests.LibraryModeBuild(useWasmSdk: False)
• Remove UseMonoRuntime from LazyLibrary.csproj

https://github.com/dotnet/sdk/blob/main/src/Workloads/Manifests/Microsoft.NET.Workload.Mono.Toolchain.Current.Manifest/WorkloadManifest.targets.in#L37

[dotnet-policy-service]

Tagging subscribers to 'arch-wasm': @lewing, @pavelsavara
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