Dovecot doesn't start after upgrading Ubuntu, how to raise ARG_MAX?

Question

After upgrading Ubuntu from 20.04 to 22.04 I'm having a problem with starting dovecot and I'm getting the following error:

$ sudo dovecot -F
doveconf: Fatal: execvp(/usr/sbin/dovecot) failed: Argument list too long

How do you raise the ARG_MAX variable?

I have tried finding solutions in ulimit, sysconf and exec.

$ sudo getconf ARG_MAX
2097152
$ getconf ARG_MAX
6291456

EDIT: Should I add something to the /etc/security/limits.conf file?

EDIT2: I have added the following to /etc/secutiry/limits.conf:

root    soft    nofile      65535
root    hard    nofile      65535

and uncommented LimitNOFILE=65536 in dovecot.service but it still throws the same error!

EDIT3:

$ sudo doveconf -n

auth_debug = yes
auth_debug_passwords = yes
auth_mechanisms = PLAIN
auth_verbose = yes
disable_plaintext_auth = no
log_path = /var/log/dovecot.log
mail_home = /home/vmail/%d/%u
mail_location = maildir:~
passdb {
  args = /etc/dovecot/dovecot-sql.conf
  driver = sql
}
protocols = imap pop3
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0666
    user = postfix
  }
  user = root
}
ssl = required
ssl_ca = </etc/ssl/certs/ca-certificates.crt
ssl_cert = </etc/letsencrypt/live/*.nl/fullchain.pem
ssl_cipher_list = ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384
ssl_dh = # hidden, use -P to show it
ssl_key = # hidden, use -P to show it
ssl_prefer_server_ciphers = yes
userdb {
  args = /etc/dovecot/dovecot-sql.conf
  driver = sql
}
local_name mail.*.nl {
  protocol imap {
    ssl_ca = </etc/ssl/certs/ca-certificates.crt
    ssl_cert = </etc/letsencrypt/live/*.nl/fullchain.pem
    ssl_key = # hidden, use -P to show it
  }
}
local_name mail.*.nl {
  protocol pop3 {
    ssl_ca = </etc/ssl/certs/ca-certificates.crt
    ssl_cert = </etc/letsencrypt/live/*.nl/fullchain.pem
    ssl_key = # hidden, use -P to show it
  }
}

Exit code: 89