Add Wasm micro build to check changes for wasm compatibility

[LoopedBard3]

Taking into account the performance-ci miss that caused dotnet/runtime#78575, it would be good to add a wasm microbenchmarks run to protect against wasm specific breaking change.

[radical]

The best way to do this would be to follow the steps from docs/benchmarking-workflow-dotnet-runtime.md which would - checkout+build-runtime+install-sdk-and-workload and run a tiny subset benchmarks.This would be closest to how we do this for dotnet-runtime-perf pipeline.

Please feel free to ping me if any help is needed with this.