Update hero images alt text

[Maroyafaied]

The alt text should be empty quotes since a descriptive alt text doesn't help screen readers.

[lpgoldstein]

@eelzi-ONRR Pleaser review that I've removed the descriptive alt text from the hero images and replaces with "" no hurry at all to check.

https://dev-onrr-frontend.app.cloud.gov/?tabs=overview

• [x] Home Hero image
• [x] compliance and enforcement hero
• [x] getting started hero
• [x] Indian resources hero
• [x] References hero
• [x] About ONRR hero
• [x] Paying hero
• [x] Reporting hero

[eelzi-ONRR]

@lpgoldstein I checked the Home pages and a second page in each section and all the hero images alt text looks good! They all are ""

[lpgoldstein]

all live and checked.