[MINOR] Fix validate_staged_release.sh

[yihua]

Change Logs

The scripts/release/validate_staged_release.sh throws the following error

Checking for binary files in source release
There were non-text files in source release. [ERROR]
 Please check below

./release/release_guide_overview.jpg: image/png; charset=binary


Performing custom Licensing Check 
There were some source files that did not have Apache License [ERROR]
./release/release_guide_overview.jpg

This PR fixes scripts/release/validate_staged_release.sh to skip checking release/release_guide* for "Binary Files Check" and "Licensing Check".

Impact

Fixes the "Binary Files Check" and "Licensing Check" for release candidates.

Risk level

none

Documentation Update

N/A

Contributor's checklist

• Read through contributor's guide
• Change Logs and Impact were stated clearly
• Adequate tests were added if applicable
• CI passed