Check compatiblity with search_api_solr 7.x-1.8

I just noticed that search_api_solr 7.x-1.8 was released on Monday. There were only two changes, one of which may apply to Sarnia. Since I can't test the interaction between the two modules at the moment, this is kind of a note to myself to do it later. Although, if anyone else wants to check it too, that would be for the best.

While testing #1944294: Allow users to update the Boost factor on fulltext fields I noticed that search_api_solr asked me to re-index all the items on the server after updating the field boosts. Of course, in the case of a Sarnia server that's not necessary or advisable. I noted the problem, but didn't do anything about it at the time. Eventually I kind of forgot about it.

Well, it turns out that's not really necessary in the case of any Solr server. Like the Sarnia issue mentions, the boost is a query parameter and shouldn't affect the contents of the index. #2441117: Change boost settingsin UI without reindex content is the issue that was just committed to search_api_solr. It should stop the re-indexing message unless it's actually necessary, which in the case of adjusting boosts it isn't. I'm betting this works ok and we don't really need to do anything on our end, but we should check. If we can get one or two tests then I bet @drunken monkey would appreciate us letting him know the results. He didn't get anyone to test his patch before he committed it.