Increment MSRV to 1.61.0

[Ogeon]

Following the change of MSRV in syn, the MSRV of Palette is incremented from 1.60.0 to 1.61.0.

[codspeed-hq]

CodSpeed Performance Report

Merging #404 will degrade performances by 16.87%

_{Comparing msrv_1_61 (37795e3) with master (28307cc)}

Summary

❌ 1 regressions
✅ 45 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	master	msrv_1_61	Change
❌	multiply_3x3	287.5 ns	345.8 ns	-16.87%

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.66%. Comparing base (28307cc) to head (37795e3).
Report is 2 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #404   +/-   ##
=======================================
  Coverage   82.66%   82.66%           
=======================================
  Files         127      127           
  Lines       19545    19545           
  Branches    19545    19545           
=======================================
  Hits        16157    16157           
  Misses       3285     3285           
  Partials      103      103           

Components	Coverage Δ
palette	82.72% <100.00%> (ø)
palette_derive	81.98% <ø> (ø)