docs: GitHub is spelled incorrectly in caching-strategies.md

[janco-absa]

Description

Update the word GiHub 3 lines under the start of that section, because it's confusing to read. It should be "GitHub"

Motivation and Context

I was reading the caching strategies and got a confused when "GiHub" was mentioned, had to to do a double take :)

How Has This Been Tested?

Nope, its only docs

Screenshots (if appropriate):

N/A

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (add or update README or docs)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[TheGiraffe3]

Good catch!