Update mjolnir antispam commit hash

Changed the commit hash in matrix_synapse_ext_spam_checker_mjolnir_antispam_git_version to latest. Fixes a Synapse ImportError with mjolnir v1.4.1 leading to a Synapse crash-loop.

roles/matrix-synapse/defaults/main.yml

@@ -525,7 +525,7 @@ matrix_synapse_ext_spam_checker_synapse_simple_antispam_config_blocked_homeserve
 # See: https://github.com/matrix-org/mjolnir#synapse-module
 matrix_synapse_ext_spam_checker_mjolnir_antispam_enabled: false
 matrix_synapse_ext_spam_checker_mjolnir_antispam_git_repository_url: "https://github.com/matrix-org/mjolnir"
-matrix_synapse_ext_spam_checker_mjolnir_antispam_git_version: "70f353fbbad0af469b1001080dea194d512b2815"
+matrix_synapse_ext_spam_checker_mjolnir_antispam_git_version: "4008e3f65d3745b9307dd31f1c5aa80c13a61a58"
 matrix_synapse_ext_spam_checker_mjolnir_antispam_config_block_invites: true
 # Flag messages sent by servers/users in the ban lists as spam. Currently
 # this means that spammy messages will appear as empty to users. Default