Update using 1.9.14 and 1.9.15 fails on unknown AruProduct values (even when not patching in said update)

1.9.14 introduced a change that checks the oracle home for relevant software versions for patching (ca6c200) instead of only WLS. The problem is, it's possible for the result of this list to contain items that are not currently supported.
The 1.9.15 release attempted to at least cover this by allowing this to fail when not patching (a8cd71a) but this change is checking too late in the process and the Image Tool will have already thrown an exception in the preceding call to FmwInstallerType.fromProductList while trying to convert the list into an AruProduct set:

weblogic-image-tool/imagetool/src/main/java/com/oracle/weblogic/imagetool/installer/FmwInstallerType.java

Line 143 in 05f63bc

.map(AruProduct::valueOf) // convert String to AruProduct enum

In our case this presented itself as the following error message:

[SEVERE ] No enum constant com.oracle.weblogic.imagetool.aru.AruProduct.OIM