retire crm-ext-01 (donate-paleo) after donate-neo launch

in #41252 (comment 2990644), @kez tested crm-ext-01 after I upgraded it and found the donate site completely broken by the PHP 8.2 upgrade. apparently, implode completely changed signature in PHP and the old signature was dropped in PHP 8, which breaks a lot of things.

exactly how much is unclear, @kez estimated just the work to estimate that work to be a few hours of work.

for now i rolled back to the php 7.4 package from bullseye, and added it to the sources.list file (although puppet might have killed the .list file already). we need to figure out a plan to go forward, either port the code, or retire the box, which is the ultimate goal once donate-neo goes to production.

update: we're going to simply retire crm-ext-01 once donate-neo launches (tpo/web/donate-neo#80).

checklist:

1. announcement (N/A)
2. retire the host in fabric (generous (1 month disk, 6 months backups?) destruction delay)
3. remove from LDAP with ldapvi
4. power-grep, includes removing puppet code around roles::civicrm_ext_2018
5. remove from tor-passwords
6. remove from DNSwl n/a
7. remove from docs
8. remove from racks n/a
9. remove from reverse DNS

Other tasks:

• Restore normal TTL on DNS entry
• Retire donate.torproject.org static component
• Archive tpo/web/donate and tpo/web/donate-static projects
• deal with the old onion service redirect (tpo/web/donate-neo#108)