Fix wasm compilation after KT-63348

[cypressious]

The suppressed warning was indicating something wrong with the code. After KT-63348 we get a compilation error

file:///C:/Users/Kirill/IdeaProjects/user-projects/kotlinx.coroutines/build/wasm/packages/kotlinx-coroutines-testWasm-test/kotlin/kotlinx-coroutines-testWasm-test.uninstantiated.mjs:269
        const wasmModule = new WebAssembly.Module(wasmBuffer);
                           ^
CompileError: WebAssembly.Module(): Compiling function #6810:"kotlinx.coroutines.test.createTestResult" failed: call[0] expected type (ref null 6), found call of type externref @+775164
    at instantiate (file:///C:/Users/Kirill/IdeaProjects/user-projects/kotlinx.coroutines/build/wasm/packages/kotlinx-coroutines-testWasm-test/kotlin/kotlinx-coroutines-testWasm-test.uninstantiated.mjs:269:28)
    at async file:///C:/Users/Kirill/IdeaProjects/user-projects/kotlinx.coroutines/build/wasm/packages/kotlinx-coroutines-testWasm-test/kotlin/kotlinx-coroutines-testWasm-test.mjs:6:18

This commit fixes the compilation and allows us to remove the warning suppression.

[dkhalanskyjb]

Please target the develop branch. See https://github.com/Kotlin/kotlinx.coroutines/blob/master/CONTRIBUTING.md

[cypressious]

Please target the develop branch. See https://github.com/Kotlin/kotlinx.coroutines/blob/master/CONTRIBUTING.md

done