Pin Werkzeug version for Flask 0.x

[bxsx]

Description of the change

On May 11, 2021, Werkzeug released a new 2.x version that are not compatible with Flask 0.x.

This PR pins compatible Werkzeug version to Flask 0.x to fix build issues:

• Werkzeug >=0.7 and < 1.0

NOTE: We have successfully built Flask 0.x with Werkzeug 1.x so far, however according to the upstream, Flask 0.x requires Werkzeug >=0.7 and < 1.0, so for sanity this PR uses the same requirements.

Type of change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Related issues

[ch85391]

Checklists

Development

• Lint rules pass locally
• The code changed/added as part of this pull request has been covered with tests
• All tests related to the changed code pass in development

Code review

• This pull request has a descriptive title and information useful to a reviewer. There may be a screenshot or screencast attached
• "Ready for review" label attached to the PR and reviewers mentioned in a comment
• Changes have been reviewed by at least one other engineer
• Issue from task tracker has a link to this pull request

[shortcut-integration]

This pull request has been linked to Clubhouse Story #85391: [CI] Flask v0.x has started to fail on Python3.5+.