postgis no longer works after dist-upgrade

[Andrew Gallagher]

After dist-upgrading from focal to jammy, postgis no longer works due to an undeclared dependency on glibc++ 3.4.29:

```
Apr 24 10:55:14 tiles2 renderd[1761]: reason: Postgis Plugin: ERROR: could not load library "/usr/lib/postgresql/12/lib/postgis-3.so": /lib/x86_64-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.29'
not found (required by /lib/x86_64-linux-gnu/libSFCGAL.so.1)#012LINE 16: )
```

This makes it both impossible to use postgis, and impossible to migrate to postgresql 14, since for a postgres upgrade both versions must be operational simultaneously.

See also https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/1907652?comments=all and https://bugs.launchpad.net/ubuntu/+source/postgis/+bug/1950772 .

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: postgis 3.2.0+dfsg-1ubuntu1
ProcVersionSignature: Ubuntu 5.4.0-177.197-generic 5.4.268
Uname: Linux 5.4.0-177-generic x86_64
ApportVersion: 2.20.11-0ubuntu82.5
Architecture: amd64
CasperMD5CheckResult: unknown
Date: Wed Apr 24 10:59:04 2024
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
RebootRequiredPkgs: Error: path contained symlinks.
SourcePackage: postgis
UpgradeStatus: Upgraded to jammy on 2024-04-23 (0 days ago)

[Andrew Gallagher (andrewg-l)]

This error went away on restart, so it's probably safe to close.