follow-up to 'Upgrade almalinux image to version 8.6'

Upgrade also dev image.

Change-Id: Iffd8baedaac36c08b105eff8024db5ea48fba220
diff --git a/almalinux/8/Dockerfile-dev b/almalinux/8/Dockerfile-dev
index 0b73848..33ccee3 100644
--- a/almalinux/8/Dockerfile-dev
+++ b/almalinux/8/Dockerfile-dev
@@ -1,4 +1,4 @@
-FROM almalinux:8.5
+FROM almalinux:8.6
 MAINTAINER Gerrit Code Review Community
 
 ARG GERRIT_WAR_URL="https://gerrit-ci.gerritforge.com/view/Gerrit/job/Gerrit-bazel-master/lastSuccessfulBuild/artifact/gerrit/bazel-bin/release.war"