[wasm] Enable tests disabled by preloading & compression endpoint issue

[maraf]

Requires dotnet/runtime#114953
Relates to dotnet/runtime#114915

[Copilot]

Pull Request Overview

This PR re-enables several tests that were previously disabled due to a System.Text.Json dependency issue by replacing the [Fact(Skip = ...)] attributes with either [RequiresMSBuildVersionFact("17.12", ...)] or by removing the skip parameter. Key changes include:

• Replacing disabled test attributes with [RequiresMSBuildVersionFact("17.12", Reason = "Needs System.Text.Json 8.0.5")] in multiple test files.
• Enabling previously skipped tests by removing the skip parameters.
• Removing commented-out attribute lines to clean up the code.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
test/Microsoft.NET.Sdk.Razor.Tests/StaticWebAssetEndpointsIntegrationTest.cs	Re-enabled tests by replacing the disabled attributes.
test/Microsoft.NET.Sdk.BlazorWebAssembly.Tests/WasmJsModulesIntegrationTests.cs	Updated test attributes to re-enable tests; one test now uses [Fact] while others use [RequiresMSBuildVersionFact].
test/Microsoft.NET.Sdk.BlazorWebAssembly.Tests/WasmBuildIntegrationTest.cs	Re-enabled a test by removing the skip parameter.
test/Microsoft.NET.Sdk.BlazorWebAssembly.Tests/BlazorWasmStaticWebAssetsIntegrationTest.cs	Re-enabled tests by replacing disabled attributes with [RequiresMSBuildVersionFact].

Comments suppressed due to low confidence (1)

test/Microsoft.NET.Sdk.BlazorWebAssembly.Tests/WasmJsModulesIntegrationTests.cs:217

• [nitpick] The test 'JsModules_CanCustomizeBlazorInitialization' is now enabled with [Fact] instead of using [RequiresMSBuildVersionFact] like its peers. Please confirm that this difference in test enabling is intentional and that the test's prerequisites are met.

[Fact]