Only setup *_PROXY env variables where needed (#7095)

no_proxy is a pain to get right, and having proxy variables present causes issues
(k8s components get proxy configuration after upgrade, see #7100)

It's better to only configure what require proxy:
- the runtime (containerd/docker/crio)
- the package manager + apt_key
- the download tasks

Tested with the following clusters
- 4 CentOS 8 nodes
- 1 Ubuntu 20.04 node

Signed-off-by: Etienne Champetier <champetier.etienne@gmail.com>

remove-node.yml

@@ -2,21 +2,6 @@
 - name: Check ansible version
   import_playbook: ansible_version.yml
 
-- hosts: all
-  gather_facts: false
-  tags: always
-  tasks:
-    - name: "Set up proxy environment"
-      set_fact:
-        proxy_env:
-          http_proxy: "{{ http_proxy | default ('') }}"
-          HTTP_PROXY: "{{ http_proxy | default ('') }}"
-          https_proxy: "{{ https_proxy | default ('') }}"
-          HTTPS_PROXY: "{{ https_proxy | default ('') }}"
-          no_proxy: "{{ no_proxy | default ('') }}"
-          NO_PROXY: "{{ no_proxy | default ('') }}"
-      no_log: true
-
 - hosts: "{{ node | default('etcd:k8s-cluster:calico-rr') }}"
   gather_facts: no
   vars_prompt: