Change the version to `2.6.1` #258

Job	Run time
build_windows (3.9)	7m 43s
build_windows (3.10)	8m 50s
build_windows (3.12)	8m 4s
build_windows (3.13)	8m 11s
build_linux (3.10)	2m 55s
build_linux (3.11)	2m 52s
build_windows (3.14)	8m 44s
build_linux (3.12)	2m 51s
build_linux (3.9)	2m 59s
build_linux (3.14)	2m 57s
build_linux (3.13)	3m 0s
build_windows (3.11)	10m 44s
test_linux (3.14, false, ubuntu-latest)	1m 56s
test_linux (3.12, false, ubuntu-latest)	1m 27s
test_linux (3.11, false, ubuntu-latest)	1m 19s
test_linux (3.10, false, ubuntu-latest)	1m 29s
test_linux (3.13, false, ubuntu-latest)	1m 40s
test_linux (3.9, false, ubuntu-latest)	1m 8s
test_windows (3.9, false, windows-latest)	3m 41s
test_windows (3.14, false, windows-latest)	3m 45s
test_windows (3.11, false, windows-latest)	3m 32s
test_windows (3.13, false, windows-latest)	3m 45s
test_windows (3.12, false, windows-latest)	3m 47s
test_windows (3.10, false, windows-latest)	4m 4s
	1h 41m 23s

Provide feedback