Make PHP 8.4 the default for the contributor container

Author: nickygerritsen

docker-contributor/Dockerfile

@@ -15,7 +15,7 @@ ENV DEBIAN_FRONTEND=noninteractive \
   DJ_SKIP_MAKE=0 \
   DJ_DB_INSTALL_BARE=0 \
   PHPSUPPORTED="8.1 8.2 8.3 8.4" \
-  DEFAULTPHPVERSION="8.3" \
+  DEFAULTPHPVERSION="8.4" \
   DEFAULTWEBSERVER="nginx" \
   APTINSTALL="apt-get install -y -o Dpkg::Options::=--force-confdef -o Dpkg::Options::=--force-confold"