Update test testDetectSwiftVersion for Swift 5.2.5

[cfiken]

Swift 5.2.5 is released. https://swift.org/download/

Now CI realm.SwiftLint (linux swift52) failed like this.
It is probably due to the swift5.2 container image update.
This PR supports Swift 5.2.5 in the test testDetectSwiftVersion.

[codecov-commenter]

Codecov Report

Merging #3299 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #3299   +/-   ##
=======================================
  Coverage   90.59%   90.59%           
=======================================
  Files         416      416           
  Lines       20349    20351    +2     
=======================================
+ Hits        18435    18437    +2     
  Misses       1914     1914           

Impacted Files	Coverage Δ
...ts/SwiftLintFrameworkTests/SwiftVersionTests.swift	100.00% <100.00%> (ø)
...ftLintFramework/Rules/Lint/PrivateOutletRule.swift	96.15% <0.00%> (-3.85%)	⬇️
...iftLintFramework/Extensions/String+SwiftLint.swift	96.36% <0.00%> (+1.81%)	⬆️

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[jpsim]

Thanks!