fix: data race on count pending Falco events

[dwisiswant0]

IMPORTANT: Please do not create a PR without creating an issue first!

(Any change needs to be discussed before proceeding. Failure to do so may result in the rejection of the pull request).

Summary

Race condition while count pending Falco events in checkFalcoEvents.

Proposed of changes

This PR fixes/implements the following bugs/features:

• [bug] race condition on checkFalcoEvents #111

How has this been tested?

Proof:

$ go test -v -cover -race -count=1 -run="TestNewWithFalcoSidekickURL" ./
=== RUN   TestNewWithFalcoSidekickURL
--- PASS: TestNewWithFalcoSidekickURL (8.19s)
PASS
coverage: 48.2% of statements
ok  	github.com/kitabisa/teler-waf	9.243s	coverage: 48.2% of statements

Closing issues

Fixe #111

Checklist:

• My code follows the code style of this project.
• My changes successfully ran and pass linters locally (run make lint).
• I have written new tests for my changes.
  • My changes successfully ran and pass tests locally.
• My change requires a change to the documentation.
  • I have updated the documentation accordingly.

[codecov-commenter]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (2914f61) 76.81% compared to head (78d7003) 78.60%.
Report is 3 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #112      +/-   ##
==========================================
+ Coverage   76.81%   78.60%   +1.78%     
==========================================
  Files           6        6              
  Lines        1113     1117       +4     
==========================================
+ Hits          855      878      +23     
+ Misses        206      187      -19     
  Partials       52       52              

Files	Coverage Δ
falcosidekick.go	54.23% <75.00%> (+37.87%)	⬆️

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.