test: transactions are not supported and throw exceptions, do not att…

…empt

the test target had a failure because of this line, it passes without it
and the underlying implementation specifically says it is not supported,
so seems the correct thing to simply not attempt the transaction

originally transactions were supported but support was removed in
commit d0f6610

unit tests have never been run in CI apparently, so this issue was latent

rsdroid/src/test/java/net/ankiweb/CollectionCreationTest.kt

@@ -27,7 +27,6 @@ class CollectionCreationTest {
         val backend = getBackend()
         backend.openCollection(":memory:")
         val database = withRustBackend(backend)
-        database.beginTransaction()
         try {
             val ver = database.query("select * from col")
             check(ver.moveToFirst()) { "no rows" }