Fix linting

[ewanwm]

Roll back to v2.15.0 of cpp-linter-action, newest version can't seem to find files to lint

closes #150

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Bencher Report

Branch	fix/fix-linting
Testbed	ubuntu-latest

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Benchmark	Latency	nanoseconds (ns)
Const Density Oscillations/1024/1024	📈 view plot ⚠️ NO THRESHOLD	1,895,788,193.00 ns
Const Density Oscillations/1024/1024_cv	📈 view plot ⚠️ NO THRESHOLD	0.01 ns
Const Density Oscillations/1024/1024_mean	📈 view plot ⚠️ NO THRESHOLD	1,902,335,269.88 ns
Const Density Oscillations/1024/1024_median	📈 view plot ⚠️ NO THRESHOLD	1,899,149,125.50 ns
Const Density Oscillations/1024/1024_stddev	📈 view plot ⚠️ NO THRESHOLD	15,047,053.30 ns
DP Propagator Const Density Oscillations/1024/1024	📈 view plot ⚠️ NO THRESHOLD	843,535,257.00 ns
DP Propagator Const Density Oscillations/1024/1024_cv	📈 view plot ⚠️ NO THRESHOLD	0.01 ns
DP Propagator Const Density Oscillations/1024/1024_mean	📈 view plot ⚠️ NO THRESHOLD	848,016,239.37 ns
DP Propagator Const Density Oscillations/1024/1024_median	📈 view plot ⚠️ NO THRESHOLD	846,792,590.00 ns
DP Propagator Const Density Oscillations/1024/1024_stddev	📈 view plot ⚠️ NO THRESHOLD	4,748,226.37 ns
Vacuum Oscillations/1024/1024	📈 view plot ⚠️ NO THRESHOLD	411,260,667.00 ns
Vacuum Oscillations/1024/1024_cv	📈 view plot ⚠️ NO THRESHOLD	0.00 ns
Vacuum Oscillations/1024/1024_mean	📈 view plot ⚠️ NO THRESHOLD	408,612,263.31 ns
Vacuum Oscillations/1024/1024_median	📈 view plot ⚠️ NO THRESHOLD	408,452,760.75 ns
Vacuum Oscillations/1024/1024_stddev	📈 view plot ⚠️ NO THRESHOLD	1,527,461.98 ns

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