Kill mutant

[martintmk]

Details on the issue fix or feature implementation

I noticed this mutant sometimes fails the build. Just ignore it as it cannot be tested.

Contributes to #1362

Confirm the following

• I started this PR by branching from the head of the default branch
• I have targeted the PR to merge into the default branch
• I have included unit tests for the issue/feature
• I have successfully run a local build

[codecov]

Codecov Report

Merging #1395 (d95ef6b) into main (472e961) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #1395   +/-   ##
=======================================
  Coverage   83.73%   83.73%           
=======================================
  Files         270      270           
  Lines        6449     6449           
  Branches     1006     1006           
=======================================
  Hits         5400     5400           
  Misses        840      840           
  Partials      209      209           

Flag	Coverage Δ
linux	?
macos	?
windows	83.73% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/Polly.Core/Retry/RetryResilienceStrategy.cs	100.00% <ø> (ø)