fix: additional safeguard for ResultSet

[AAfghahi]

SUMMARY

This is a small change to isAdmin in ResultSet, which adds an additional safeguard. This stems from: #14741 (comment)

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

N/A

TESTING INSTRUCTIONS

Go to SQL Editor, choose 100,000 as the amount of results in result dropdown.
Run a legitimate query as an administrator.

Your message should be:
The number of results displayed is limited to 10000 by the configuration DISPLAY_MAX_ROWS. Please add additional limits/filters or download to csv to see more rows up to the 100000 limit.

ADDITIONAL INFORMATION

• Has associated issue:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[codecov]

Codecov Report

Merging #14953 (effb814) into master (723a671) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master   #14953   +/-   ##
=======================================
  Coverage   77.59%   77.59%           
=======================================
  Files         965      965           
  Lines       49436    49436           
  Branches     6247     6247           
=======================================
  Hits        38360    38360           
  Misses      10875    10875           
  Partials      201      201           

Flag	Coverage Δ
javascript	72.42% <100.00%> (ø)

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Impacted Files	Coverage Δ
...erset-frontend/src/SqlLab/components/ResultSet.tsx	67.42% <100.00%> (ø)

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