Remove --use-deprecated legacy-resolver flag

The pip team is planning to depreciate the
'--use-deprecated legacy-resolver'install option.
While a firm date has yet to be set, We need to be
ready for the change.

Test Plan*:

PASS: Verified that tox runs without issues
PASS: Generate portieris package.
PASS: Upload and apply portieris package and check if pod
      is running.

Note(*): Tested on kubernetes 1.21.8

Closes-bug: 1966072
Signed-off-by: Karla Felix <karla.karolinenogueirafelix@windriver.com>
Change-Id: Ifc48062f95f3bc44de4a1e1703f9e04b8118d430

python-k8sapp-portieris/k8sapp_portieris/tox.ini

@@ -20,8 +20,7 @@ sitepackages = False
 whitelist_externals = bash
                       find
 
-install_command = pip install \
-    -v -v -v --use-deprecated legacy-resolver \
+install_command = pip install -v -v -v \
     -c{toxinidir}/upper-constraints.txt \
     -c{env:UPPER_CONSTRAINTS_FILE:https://opendev.org/openstack/requirements/raw/branch/stable/stein/upper-constraints.txt} \
     {opts} {packages}
@@ -73,8 +72,7 @@ commands =
 
 [testenv:py39]
 basepython = python3.9
-install_command = pip install \
-    -v -v -v --use-deprecated legacy-resolver \
+install_command = pip install -v -v -v \
     -c{toxinidir}/upper-constraints.txt \
     -c{env:UPPER_CONSTRAINTS_FILE:https://opendev.org/starlingx/root/raw/branch/master/build-tools/requirements/debian/upper-constraints.txt} \
     {opts} {packages}