Fix tests for 2.10 release

[wanliAlex]

• Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes/features)
• Docs have been added / updated (for bug fixes / features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
  Test fix

• What is the current behavior? (You can also link to an open issue here)

• 1. We don't have no-model end-to-end tests
• 2. PY-Marqo tries to decode it as JSON and gets an error when the response isn't JSON
• 3. Version check tests are not working properly

• What is the new behavior (if this is a feature change)?

• 1. Add no-model end-to-end tests
• 2. Fix a bug where PY-Marqo tries to decode it as JSON and gets an error when the response isn't JSON
• 3. Fix a bug where version check tests are not working properly

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)

• Other information: