Fix #6557 - Fix slow down on multiple fetchMore

[bendenoz]

Having a go at this.

Default fetch policy for fetchMore creates many unreleased cache watches.
The cache is managed in the updateQuery callback anyway, so there should not be a need for network-only in fetchMore.

This seems to fix slowdowns for our use case

[benjamn]

@bendenoz This has been fixed for a long time (since #6221, or @apollo/[email protected], or any non-prerelease version of the @apollo/client package). What's preventing you from updating, out of curiosity?

[bendenoz]

Thanks for your reply @benjamn, I'm always a bit wary about big upgrades on a production project, but I guess we will try now.
And #6557 is still somehow active so I assumed the issue was still around.

[bendenoz]

ok it's working fine with apollo 3 so we're in the process of upgrading.
thanks !