I had a paid summer internship in Washington for 3 months but reside in Arizona. Is the income I made in Washington supposed to be part of my Arizona taxable income?

Unfortunately yes. If you consider AZ to be your permanent residence, then you will need to include all income from all sources (including your WA internship income) on your AZ resident state income tax return.

You will have no WA state filing requirement because WA has no individual state income tax filing requirement.

I am an international student attending Arizona State University. I moved out of Arizona for 3 months during the summer (May - August) for an internship in WA. Do i still have to pay taxes in Arizona for the internship in WA as i am a non resident alien. I am filing taxes using Sprintax