Add `bigdecimal` as a dependency #21

Job	Run time
cross-compile-linux	9s
install-windows-native (2.7)	4m 40s
cross-compile-windows (x64-mingw32)	59s
cross-compile-windows (x86-mingw32)	58s
install-macos-m1 (2.7)	1m 3s
install-windows-native (3.0)	2m 27s
cross-compile-windows (x64-mingw-ucrt)	1m 5s
install-macos-m1 (3.0)	25s
install-windows-native (3.1)	2m 25s
install-macos-m1 (3.1)	27s
install-macos-m1 (3.2)	24s
install-windows-native (3.2)	2m 58s
install-macos-m1 (3.3)	26s
install-windows-native (3.3)	3m 21s
test-linux (2017, 2.7)	1m 24s
test-linux (2017, 3.0)	1m 9s
test-linux (2017, 3.1)	1m 16s
test-linux (2017, 3.2)	1m 21s
test-linux (2017, 3.3)	1m 21s
test-linux (2019, 2.7)	1m 30s
test-linux (2019, 3.0)	1m 29s
test-linux (2019, 3.1)	1m 14s
test-linux (2019, 3.2)	1m 11s
test-linux (2019, 3.3)	1m 24s
test-linux (2022, 2.7)	1m 30s
test-linux (2022, 3.0)	1m 14s
test-linux (2022, 3.1)	1m 14s
test-linux (2022, 3.2)	1m 10s
test-linux (2022, 3.3)	1m 10s
install-windows-mingw (2.7)	3m 37s
install-windows-ucrt (3.1)	1m 3s
install-windows-mingw (3.0)	1m 43s
test-windows-mingw (2019, 2.7)	3m 28s
install-windows-ucrt (3.2)	1m 12s
test-windows-mingw (2019, 3.0)	1m 50s
test-windows-ucrt (2019, 3.1)	2m 51s
install-windows-ucrt (3.3)	3m 19s
test-windows-mingw (2022, 2.7)	3m 23s
test-windows-ucrt (2019, 3.2)	2m 20s
test-windows-mingw (2022, 3.0)	2m 13s
test-windows-ucrt (2019, 3.3)	2m 50s
test-windows-ucrt (2022, 3.1)	2m 5s
test-windows-ucrt (2022, 3.2)	2m 32s
test-windows-ucrt (2022, 3.3)	2m 43s
	1h 18m 33s

Provide feedback