cross compilation for linux on macOS fails

compilation fails with

```
⋮
.build/checkouts/SQLite.swift/Sources/SQLite/Core/Backup.swift:32:8: error: no such module 'CSQLite'
 30 | import SQLCipher
 31 | #elseif os(Linux)
 32 | import CSQLite
    |        `- error: no such module 'CSQLite'
 33 | #else
 34 | import SQLite3
⋮
```

when invoked with command `swift build --swift-sdk x86_64-swift-linux-musl` 
