Do not install pip in advance

... because the package should be installed when needed.

Depends-on: https://review.opendev.org/c/openstack/puppet-tempest/+/900618
Change-Id: Ie1f71f933cedbd1ab0361e68a09b11cf1da585d4

playbooks/prepare-node-common.yaml

@@ -46,19 +46,6 @@
       when:
         - ansible_os_family == 'RedHat'
 
-    - block:
-      - name: install required packages (CentOS)
-        dnf:
-          name: "{{ item }}"
-          state: present
-        become: true
-        ignore_errors: true
-        with_items:
-          - python3-pip
-      when:
-        - ansible_os_family == 'RedHat'
-        - ansible_distribution == 'CentOS'
-
     - name: Install Ruby dependencies (Ubuntu)
       apt:
         name: "{{ item }}"
@@ -71,7 +58,6 @@
         - libxslt-dev
         - ruby-dev
         - zlib1g-dev
-        - python3-pip
 
     - name: Install Ruby dependencies (Debian)
       apt:
@@ -86,4 +72,3 @@
         - libxslt1-dev
         - ruby-dev
         - zlib1g-dev
-        - python3-pip