Increase term-index SPARQL page size from 2500 to 5000

Bulk reindexing is dominated by the per-page SPARQL fetch from the
triplestore (~24 of 36 hours in the last full staging run, ~71% of
indexing time). Doubling the page size halves the number of page
queries and their per-query setup overhead, at the cost of higher
peak memory per page. Performance change only; no behavior change.

Author: mdorf

lib/ontologies_linked_data/services/submission_process/operations/submission_indexer.rb

@@ -40,7 +40,7 @@ def unindex_existing?(options)
 
       def index(logger, commit: true, optimize: true, commit_within: 30_000, generate_csv: true, unindex_existing: true)
         page = 0
-        size = 2500
+        size = 5000
         count_classes = 0
         previous_requested_lang = RequestStore.store[:requested_lang]