Upgrade docker SDK client version (#16593)

What is the motivation for this PR?
Previously the upgrade of requests package caused a compatibility issue with the docker SDK client. A workaround was introduced in the playbook to force install a lower version requests package.

After the issue was fixed in the docker SDK client side, the workaround code can be removed.

How did you do it?
This change removed the workaround code and upgraded the docker client to version 7.1.0.

How did you verify/test it?
Tested add/remove topo using the testbed-cli.sh

ansible/roles/vm_set/tasks/docker.yml

@@ -91,7 +91,7 @@
     environment: "{{ proxy_env | default({}) }}"
     ignore_errors: yes
   - name: Install python packages
-    pip: name=docker version=6.1.0 state=forcereinstall executable={{ pip_executable }}
+    pip: name=docker version=7.1.0 state=forcereinstall executable={{ pip_executable }}
     become: yes
     environment: "{{ proxy_env | default({}) }}"
   when: pip_executable=="pip3"

ansible/roles/vm_set/tasks/main.yml

@@ -146,19 +146,10 @@
 - include_tasks: docker.yml
   when: package_installation|bool
 
-- name: Update python3 packages
-  block:
-    # Workaround for '"Error connecting: Error while fetching server API version: Not supported URL scheme http+docker'
-    # See https://github.com/docker/docker-py/issues/3256
-  - name: Remove old requests package >=2.32.0
-    pip: name=requests state=absent executable={{ pip_executable }}
-    become: yes
-    environment: "{{ proxy_env | default({}) }}"
-    ignore_errors: yes
-  - name: Install requests package <2.32.0
-    pip: name=requests version=2.31.0 state=present executable={{ pip_executable }}
-    become: yes
-    environment: "{{ proxy_env | default({}) }}"
+- name: Install requests package
+  pip: name=requests version=2.32.3 state=present executable={{ pip_executable }}
+  become: yes
+  environment: "{{ proxy_env | default({}) }}"
   when: pip_executable=="pip3"
 
 - name: Ensure {{ ansible_user }} in docker,sudo group