Upgrade superset to 1.5.0

[accorvin]

Description

Upgrade the superset image to version 1.5.0.

Note that the configuration to build the new image can be found here.

How Has This Been Tested?

I deployed superset in a development OC 4.11 cluster from the current version (1.4.1) then updated the deployment to use this new image. All Superset functionality continued working as normal.

Merge criteria:

• The commits are squashed in a cohesive manner and have meaningful messages.
• Testing instructions have been added in the PR body (for PRs involving changes that are not immediately obvious).
• The developer has manually tested the changes and verified that the changes work

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: crobby

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• superset/OWNERS [crobby]

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