feat: official Debian 11 compatibility (#176)

Introduce Debian 11 compatibility
Based on CIS_Debian_Linux_11_Benchmark_v1.0.0

After review, here are the notable changes :
 - Harden /var/log more (noexec,nodev,nosuid)
 - Harden /var/log/audit more (noexec,nodev,nosuid)
 - Harden /home more (nosuid)
 - Disable cramfs
 - Fix 5.3.4_acc_pam_sha512.sh
 - Deprecate Debian 9 and remove useless docker images

NB : more audit log rules have been introduced and will be inserted in the checks later
Fix #158

tests/hardening/1.1.12.1_var_log_audit_noexec.sh

@@ -0,0 +1,16 @@
+# shellcheck shell=bash
+# run-shellcheck
+test_audit() {
+    describe Running on blank host
+    register_test retvalshouldbe 0
+    dismiss_count_for_test
+    # shellcheck disable=2154
+    run blank /opt/debian-cis/bin/hardening/"${script}".sh --audit-all
+
+    ##################################################################
+    # For this test, we only check that it runs properly on a blank  #
+    # host, and we check root/sudo consistency. But, we don't test   #
+    # the apply function because it can't be automated or it is very #
+    # long to test and not very useful.                              #
+    ##################################################################
+}