flatpak and kitinerary-extractor not found - PHP Warning

Steps to reproduce

Simply use the mail app

Expected behavior

No PHP Warning

Actual behavior

[14-Jan-2023 12:20:21] WARNING: [pool owncloud.example.one] child 19025 said into stderr: "/var/www/vhosts/example.one/owncloud.example.one/apps/mail/vendor/christophwurst/kitinerary-bin/src/../bin/kitinerary-extractor: /lib/x86_64-linux-gnu/libm.so.6: version GLIBC_2.29' not found (required by /var/www/vhosts/example.one/owncloud.example.one/apps/mail/vendor/christophwurst/kitinerary-bin/src/../bin/kitinerary-extractor)" [14-Jan-2023 12:20:21] WARNING: [pool owncloud.example.one] child 19025 said into stderr: "/var/www/vhosts/example.one/owncloud.example.one/apps/mail/vendor/christophwurst/kitinerary-bin/src/../bin/kitinerary-extractor: /lib/x86_64-linux-gnu/libm.so.6: version GLIBC_2.35' not found (required by /var/www/vhosts/example.one/owncloud.example.one/apps/mail/vendor/ch
ristophwurst/kitinerary-bin/src/../bin/kitinerary-extractor)"
[14-Jan-2023 12:20:21] WARNING: [pool owncloud.example.one] child 19025 said into stderr: "/var/www/vhosts/example.one/owncloud.example.one/apps/mail/vendor/christophwurst/kitinerary-bin/src/../bin/kitinerary-extractor: /lib/x86_64-linux-gnu/libc.so.6: version GLIBC_2.34' not found (required by /var/www/vhosts/example.one/owncloud.example.one/apps/mail/vendor/christophwurst/kitinerary-bin/src/../bin/kitinerary-extractor)" [14-Jan-2023 12:20:21] WARNING: [pool owncloud.example.one] child 19025 said into stderr: "/var/www/vhosts/example.one/owncloud.example.one/apps/mail/vendor/christophwurst/kitinerary-bin/src/../bin/kitinerary-extractor: /lib/x86_64-linux-gnu/libc.so.6: version GLIBC_2.33' not found (required by /var/www/vhosts/example.one/owncloud.example.one/apps/mail/vendor/christophwurst/kitinerary-bin/src/../bin/kitinerary-extractor)"
[14-Jan-2023 12:20:21] WARNING: [pool owncloud.example.one] child 19025 said into stderr: "sh: 1: flatpak: not found"
[14-Jan-2023 12:20:21] WARNING: [pool owncloud.example.one] child 19025 said into stderr: "sh: 1: kitinerary-extractor: n

Mail app version

2.2.2

Mailserver or service

Postfix

Operating system

Debian 10

PHP engine version

PHP 8.1

Web server

Nginx

Database

MariaDB

Additional info

I'm seeing this problem since installing latest Nextcloud 25.0.2, and the latest version of the mail app. I'm seeing it on both installations that I manage, the other one runs PHP 8.0.

Start by reproducing the warning while using the Mail app on Debian 10 with the reported PHP versions, then inspect how the app invokes kitinerary-extractor and flatpak. Compare the required GLIBC versions with the host environment and verify that the completed work no longer emits the reported PHP warnings.