Tox/Zuul: Change parent job to tox

Some STX Zuul jobs are using openstack jobs as parents.
The problem with that is that openstack has their own
upper-requirement files and job definitions and they aren't
always valid for the STX cases.

Test Plan:
pass: zuul

Partial-Bug: 2121603

Change-Id: I36f8e7117ecfff1887e9d9fc8207601193bf00d4
Signed-off-by: Leonardo Fagundes Luz Serrano <Leonardo.FagundesLuzSerrano@windriver.com>

.zuul.yaml

@@ -7,18 +7,42 @@
       - stx-bandit-jobs
     check:
       jobs:
-        - starlingx-common-tox-linters
-        - starlingx-common-tox-pep8
-        - starlingx-common-tox-pylint
+        - metal-tox-linters
+        - metal-tox-pep8
+        - metal-tox-pylint
     gate:
       jobs:
-        - starlingx-common-tox-linters
-        - starlingx-common-tox-pep8
-        - starlingx-common-tox-pylint
+        - metal-tox-linters
+        - metal-tox-pep8
+        - metal-tox-pylint
     post:
       jobs:
         - stx-metal-upload-git-mirror
 
+- job:
+    name: metal-tox-linters
+    parent: tox
+    description: Run linters for metal repo
+    nodeset: debian-bullseye
+    vars:
+      tox_envlist: linters
+
+- job:
+    name: metal-tox-pep8
+    parent: tox
+    description: Run pep8 for metal repo
+    nodeset: debian-bullseye
+    vars:
+      tox_envlist: pep8
+
+- job:
+    name: metal-tox-pylint
+    parent: tox
+    description: Run pylint for metal repo
+    nodeset: debian-bullseye
+    vars:
+      tox_envlist: pylint
+
 - job:
     name: flock-devstack-metal
     parent: flock-devstack-base-min