Fixed #33124 -- Avoided accessing the database connections when not necessary.

[kezabelle]

Ticket is 33124, following on from ticket 33025 which was PR 14769.

• Repeated access to connections[alias] should be cached into a local variable wherever possible to avoid asking the Local for the value twice.
• Asking for connections[alias] a single time should be deferred until absolutely necessary (ie: local to the if branch, or as the last part of an if chained comparison, etc)

[felixxm]

@kezabelle These changes looks good, thanks 👍 Is there anything left for this patch? If not, I can squash & merge.

[kezabelle]

I think this was all of the ones (outside of tests) which made sense, except for the change which Nick pointed out was problematic.

I think there's a couple of others that could be done, like eg: django.contrib.sites.management.create_default_site but they are "one and done" operations, which won't net any positive change and just muddy the git annotation history...

I can do another pass to find and do those if you'd prefer, though.

[felixxm]

I can do another pass to find and do those if you'd prefer, though.

No need, thanks 👍