setup: disable entry points if opt deps not installed

* Entry points will now only be installed if the required optional
  dependencies are installed.

setup.cfg

@@ -169,7 +169,7 @@ cylc.command =
     remote-init = cylc.flow.scripts.remote_init:main
     remote-tidy = cylc.flow.scripts.remote_tidy:main
     remove = cylc.flow.scripts.remove:main
-    report-timings = cylc.flow.scripts.report_timings:main
+    report-timings = cylc.flow.scripts.report_timings:main [report-timings]
     scan = cylc.flow.scripts.scan:cli
     set-verbosity = cylc.flow.scripts.set_verbosity:main
     show = cylc.flow.scripts.show:main
@@ -185,11 +185,11 @@ cylc.command =
 cylc.main_loop =
     health_check = cylc.flow.main_loop.health_check
     auto_restart = cylc.flow.main_loop.auto_restart
-    log_data_store = cylc.flow.main_loop.log_data_store
-    log_main_loop = cylc.flow.main_loop.log_main_loop
-    log_memory = cylc.flow.main_loop.log_memory
+    log_data_store = cylc.flow.main_loop.log_data_store [main_loop-log_data_store]
+    log_main_loop = cylc.flow.main_loop.log_main_loop [main_loop-log_main_loop]
+    log_memory = cylc.flow.main_loop.log_memory [main_loop-log_memory]
     reset_bad_hosts = cylc.flow.main_loop.reset_bad_hosts
-# NOTE: all entry points should be listed here even if Cylc Flow does not
+# NOTE: all entry points should be listed here even if Cylc Flow does not
 # provide any implementations, to make entry point scraping easier
 cylc.pre_configure =
 cylc.post_install =