Proposal - make 5.33 the last CiviCRM version to support php 7.1 (agreed) and mysql 5.6 (deferred) (& equivalent MariaDB version)

This extracts from our end-of-life planning for old mysql versions #1681 (closed) and php versions #1528 (closed) and makes the proposal that the 5.33 ESR is the last version to support php 7.1 and mysql 5.6. This means that sites can get up to 8 more months support on these versions for $120.

Background/ notes

• we have aligned recent end of life for php & mysql versions with ESR versions because it means that if there is an economic value to delaying upgrading people can opt in. If $120 doesn't seem like value for money then it's hard to make the case it is worth $x in developer time

• we have been announcing that both are EOL for ? 6 months? via system checks

• we haven't had a lot of push back from sites about previous EOL efforts on php versions. Generally once we stop supporting a php version there are a reasonable amount of breaking changes after the first 2-3 months

• we had annecdotal evidence from 2 partners that getting off mysql 5.5 was tricky for some sites. OTOH there are unlikely to be any breaking changes for quite some time for 5.6 sites for quite some time. It's likely they could continue to use 5.6 for a year or more after we stop supporting it - we just get to say 'sorry not supported' when those weird edge cases pop up around row format or it there is some unforseen reason for a breaking change

• mysql 8.0 is about to be released

• php 8.0 is about to be released

• generally our ability to support newer mysql versions / php versions has been delayed by difficulties around legacy support and we have effectively supported old versions at the expense of newer versions

• php stopped supporting php 7.1 about a year ago

• Oracle still appears to support php 5.6 (not sure if it's for free or not)