devel/spirv-llvm-translator: unbreak build after 30e46ca60676

> Checking for pkg-plist issues (check-plist)

> Parsing plist

> Checking for items in STAGEDIR missing from pkg-plist

Error: Orphaned: llvm18/lib/libLLVMSPIRVLib.so.18.1

> Checking for items in pkg-plist which are not in STAGEDIR

Error: Missing: llvm18/lib/libLLVMSPIRVLib.so.18

> Error: Plist issues found.

• Error code 1

Reported by: pkg-fallout