fix: running shorebird command with both ios-framework and aar conflicts in release directory

[bryanoltman]

To reproduce, in the add-to-app sample, run shorebird release -p aar,ios-framework --release-verison=1.2.3. Notice that the aar artifacts (because the aar release is run first) are overwritten by the ios-framework artifacts.

We should probably write these out to different release directories.

[eseidel]

Can we just mark this as not supported for now (log?) and punt this?