Fix build:wasm:dev for --dev builds (#6038)

This is useful since it preserves Rust backtraces in WASM.

scripts/build-wasm-dev.ps1

@@ -0,0 +1,18 @@
+# Stop the script when a cmdlet or a native command fails
+# from https://www.meziantou.net/stop-the-script-when-an-error-occurs-in-powershell.htm
+$ErrorActionPreference = 'Stop'
+$PSNativeCommandUseErrorActionPreference = $true
+
+rm -Recurse -Force rust/kcl-wasm-lib/pkg
+mkdir -p rust/kcl-wasm-lib/pkg
+rm -Recurse -Force rust/kcl-lib/bindings
+
+cd rust
+$env:RUSTFLAGS='--cfg getrandom_backend="wasm_js"'
+wasm-pack build kcl-wasm-lib --dev --target web --out-dir pkg
+$env:RUSTFLAGS=''
+cargo test -p kcl-lib export_bindings
+cd ..
+
+copy rust\kcl-wasm-lib\pkg\kcl_wasm_lib_bg.wasm public
+yarn fmt:generated