Use latest pip & pip-tools in jenkins_env (#29004)

* fix: replace pip-sync with pip install in env creation

* fix: use pip-tools==6.4.0 with pip==21.3

requirements/edx/pip-tools.txt

@@ -10,7 +10,7 @@ click==7.1.2
     #   pip-tools
 pep517==0.11.0
     # via pip-tools
-pip-tools==6.3.0
+pip-tools==6.4.0
     # via -r requirements/edx/pip-tools.in
 tomli==1.2.1
     # via pep517

scripts/jenkins-common.sh

@@ -48,6 +48,7 @@ source $VENV_PATH/edx-venv/bin/activate
 # Hack to fix up egg-link files given that the virtualenv is not relocatable
 sed -i "s|^/home/jenkins/shallow-clone|`pwd`|" -- \
     $VENV_PATH/edx-venv/lib/python*/site-packages/*.egg-link
+pip install pip==21.3
 pip install -qr requirements/edx/pip-tools.txt
 pip-sync -q requirements/edx/testing.txt requirements/edx/django.txt