Remove Windows 32-bit

[cg2121]

Description

Removes Windows 32-bit from the GItHub workflow.

Motivation and Context

Since OBS 28 doesn't support 32-bit, it is pointless to build 32-bit by default. If developers need 32-bit for whatever reason, they can just add this line back in, as the backend scripts still support it.

How Has This Been Tested?

Ran workflow.

Types of changes

• Code cleanup (non-breaking change which makes code smaller or more readable)

Checklist:

• [x] My code has been run through clang-format.
• [x] I have read the contributing document.
• [x] My code is not on the master branch.
• [x] The code has been tested.
• [x] All commit messages are properly formatted and commits squashed where appropriate.
• [x] I have included updates to all appropriate documentation.