Update stage-build to run tox sequentially

Change-Id: I967f19a8c35700290e93c9d8bd863b63b7c2d239
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>

devops-stages/stage-build.sh

@@ -37,9 +37,8 @@ dist_ro_vim_vmware
 dist_ro_vim_gcp"
 
 TOX_ENV_LIST="$(echo $PACKAGES | sed "s/ /,/g")"
-PROCESSES=$(expr `nproc --a` / 2)
 
-TOX_PARALLEL_NO_SPINNER=1 tox -e $TOX_ENV_LIST --parallel $PROCESSES
+TOX_PARALLEL_NO_SPINNER=1 tox -e $TOX_ENV_LIST
 
 # Copying packages
 # RO plugin

releasenotes/notes/update_stage_build-49b24abdeba0e581.yaml

+#######################################################################################
+# Copyright ETSI Contributors and Others.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#######################################################################################
+---
+other:
+  - |
+    Update stage-build to run tox sequentially.