Update phpunit a little to decide when to fail on deprecations

PHPUnit 10.5.47 and later know the flag `--do-not-fail-on-deprecation`, which allows us to make it not exit with code 1
in case of deprecations on the second run of the script. That second run uses the lowest valid dependencies, which might
contain deprecations when used with newer versions of PHP, but still are acceptable versions, and should not make our
tests fail.

Author: pabzm

.ci/run_tests.sh

@@ -10,10 +10,11 @@ composer require $COMPOSER_ARGS "kolab/net_ldap3:~1.1.4" --no-update
 composer update $COMPOSER_ARGS --prefer-dist --no-interaction --no-progress
 
 # Execute tests.
-vendor/bin/phpunit -c tests/phpunit.xml --fail-on-warning --fail-on-risky
+vendor/bin/phpunit -c tests/phpunit.xml --fail-on-warning --fail-on-risky --display-deprecations
 
 # Downgrade dependencies to the lowest versions.
 composer update $COMPOSER_ARGS --prefer-dist --prefer-stable --prefer-lowest --no-interaction --no-progress --optimize-autoloader
 
-# Execute tests again.
-vendor/bin/phpunit -c tests/phpunit.xml --fail-on-warning --fail-on-risky
+# Execute tests again. We do not want this run to fail due to deprecations though, because those can only occur from
+# (older) dependencies, which we migh still consider good enough.
+vendor/bin/phpunit -c tests/phpunit.xml --fail-on-warning --fail-on-risky --display-deprecations --do-not-fail-on-deprecation

composer.json

@@ -26,7 +26,7 @@
         "phpstan/phpstan": "^2.0",
         "phpstan/phpstan-deprecation-rules": "^2.0",
         "phpstan/phpstan-strict-rules": "^2.0",
-        "phpunit/phpunit": "^10.5.45 || ^11.0",
+        "phpunit/phpunit": "^10.5.47 || ^11.0",
         "roundcube/acl": "*",
         "roundcube/additional_message_headers": "*",
         "roundcube/archive": "*",