ENH: Suppress false warnings for CI

pip ugrade warnings showed up on the dashboard

These are not relevant, and need to be suppressed.

Author: hjmjohnson

Utilities/Testing/azure-pipelines.yml

@@ -20,6 +20,8 @@ jobs:
 
         git clone -b dashboard --single-branch https://github.com/InsightSoftwareConsortium/ITKExamples.git ITKExamples-dashboard
 
+        # Suppress pip upgrade warning
+        export PIP_DISABLE_PIP_VERSION_CHECK=1
         sudo pip3 install ninja
         sudo apt-get update
         sudo apt-get install -y python3-venv
@@ -47,6 +49,8 @@ jobs:
 
         git clone -b dashboard --single-branch https://github.com/InsightSoftwareConsortium/ITKExamples.git ITKExamples-dashboard
 
+        # Suppress pip upgrade warning
+        export PIP_DISABLE_PIP_VERSION_CHECK=1
         sudo pip3 install ninja
 
         c++ --version
@@ -65,6 +69,8 @@ jobs:
     - script: |
         git clone -b dashboard --single-branch https://github.com/InsightSoftwareConsortium/ITKExamples.git ITKExamples-dashboard
 
+        # Suppress pip upgrade warning
+        set PIP_DISABLE_PIP_VERSION_CHECK=1
         pip3 install ninja
 
         cmake --version