fix: Add missing WER handler on Windows

[bitsandfoxes]

Fixes #1866

We're currently very explicit with what we copy over from the sentry-native build

sentry-unity/Directory.Build.targets

Lines 212 to 220 in 4df9538

	<Exec WorkingDirectory="$(SentryNativeRoot)" Command="cmake -B build -D SENTRY_BACKEND=crashpad -D SENTRY_SDK_NAME=sentry.native.unity -S ."></Exec>
	<Exec WorkingDirectory="$(SentryNativeRoot)" Command="cmake --build build --target sentry --config RelWithDebInfo --parallel"></Exec>
	<Exec WorkingDirectory="$(SentryNativeRoot)" Command="cmake --build build --target crashpad_handler --config Release --parallel"></Exec>
	<ItemGroup>
	<NativeSdkArtifacts Include="$(SentryNativeRoot)build/crashpad_build/handler/Release/crashpad_handler.exe" />
	<NativeSdkArtifacts Include="$(SentryNativeRoot)build/RelWithDebInfo/sentry.dll" />
	<NativeSdkArtifacts Include="$(SentryNativeRoot)build/RelWithDebInfo/sentry.pdb" />
	</ItemGroup>

We need to include the wer handler as well.

[bruno-garcia]

Do we have anything on the docs about this