Maps: Make all maps mutable

[melloware]

Describe the bug

See: quarkusio/quarkus#23612 (comment)

Quinoa version

2.3.5

Quarkus version

3.8.0

Build / Runtime

Vite

Package Manager

None

Steps to reproduce the behavior

Failing unit test in Quarkus Superheroes

@QuarkusTest
@TestProfile(QuinoaTestProfiles.EnableAndRunTests.class)
class AllWebUITest {
  @Test
  void runTest() {
    // we don't need anything here, it will run the package.json "test"
  }
}

Expected behavior

No response