fix: use IIFE

[bicstone]

No description provided.

[codecov]

Codecov Report

Merging #26 (b924b4e) into main (af2e9d4) will not change coverage.
The diff coverage is 100.00%.

❗ Current head b924b4e differs from pull request most recent head b57b940. Consider uploading reports for the commit b57b940 to get more accurate results

@@            Coverage Diff            @@
##              main       #26   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            4         4           
  Lines           21        23    +2     
  Branches         5         5           
=========================================
+ Hits            21        23    +2     

Impacted Files	Coverage Δ
src/gatsby-browser.ts	100.00% <100.00%> (ø)
src/gatsby-ssr.ts	100.00% <100.00%> (ø)

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more