Add a test for pint ci with no changes

[github-actions[bot]]

Benchmark diff:

goos: linux
goarch: amd64
pkg: github.com/cloudflare/pint/cmd/pint
cpu: AMD EPYC 7763 64-Core Processor                
              │   old.txt   │              new.txt               │
              │   sec/op    │   sec/op     vs base               │
FindEntries-4   39.69m ± 2%   39.98m ± 8%       ~ (p=0.143 n=10)
CheckRules-4     8.533 ± 2%    8.506 ± 2%       ~ (p=0.436 n=10)
geomean         582.0m        583.1m       +0.20%

              │   old.txt    │               new.txt               │
              │     B/op     │     B/op      vs base               │
FindEntries-4   27.41Mi ± 0%   27.41Mi ± 0%       ~ (p=0.796 n=10)
CheckRules-4    976.7Mi ± 0%   976.5Mi ± 0%       ~ (p=0.684 n=10)
geomean         163.6Mi        163.6Mi       -0.01%

              │   old.txt   │              new.txt               │
              │  allocs/op  │  allocs/op   vs base               │
FindEntries-4   131.9k ± 0%   131.9k ± 0%       ~ (p=0.485 n=10)
CheckRules-4    14.19M ± 0%   14.19M ± 0%       ~ (p=0.579 n=10)
geomean         1.368M        1.368M       -0.00%

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 94.95%. Comparing base (9468ff8) to head (0f7e6b8).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1090 +/- ## ========================================== + Coverage 94.90% 94.95% +0.05% ========================================== Files 102 102 Lines 10197 10197 ========================================== + Hits 9677 9683 +6 + Misses 365 361 -4 + Partials 155 153 -2 ```

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