searcher: remove hardcoded timeout in fetch

Created by: keegancsmith

We have a passed in context which is managed by the diskcache.Store. Lets rely on that instead of using a hardcoded timeout. This will likely help remove an error that occurs on large monorepos. Currently diskcache.Store has a timeout of 10min, but here we had it set to 2min. So we effectively never waited more than 2min. Lets be consistent and also wait 10min.