[dotnet.js] is not incremental

[jjonescz]

SDK version: 10p5 or local build (feb621b704347e6fb72b816a257f1ba2fdc6a385)
Steps to reproduce:

1. dotnet new blazorwasm
2. dotnet build
3. dotnet build -bl -question

Expected: success
Actual: fails with

MSBUILD : error : Building target "_BuildCopyStaticWebAssetsPreserveNewest" partially, because some output files are out of date with respect to their input files.

And in the binlog I can see the problem is obj\Debug\net10.0\dotnet.js.

[MackinnonBuck]

cc @javiercn

[maraf]

It happens for .NET 9 as well

Building target "_BuildCopyStaticWebAssetsPreserveNewest" partially, because some output files are out of date with respect to their input files. [/Users/marekfisera/Development/samples/BlazorWasm/BlazorWasm.csproj]