Test with multiple toolchain versions

[kateinoigakukun]

No description provided.

[github-actions]

Time Change: +3,569ms (23%) 🚨

Total Time: 15,218.75ms

Test name	Duration	Change
Serialization/Write JavaScript number directly	274.75ms	+46.25ms (16%)	⚠️
Serialization/Write JavaScript string directly	299.5ms	+64.5ms (21%)	🚨
Serialization/Swift Int to JavaScript	4,967.75ms	+1,286ms (25%)	🚨
Serialization/Swift String to JavaScript	5,024.5ms	+1,225.75ms (24%)	🚨
Object heap/Increment and decrement RC	4,652.25ms	+946.5ms (20%)	🚨

_{performance-action}

[MaxDesiatov]

@kateinoigakukun I guess we should also test with Ubuntu 20.04, but I don't see where the exact Ubuntu version is passed from the matrix. I don't think swiftenv detects that automatically, does it?

[kateinoigakukun]

@MaxDesiatov swiftenv doesn't anything around arch but install script does it

JavaScriptKit/scripts/install-toolchain.sh

Lines 25 to 29 in 5d7c353

	if [ $(grep RELEASE /etc/lsb-release) == "DISTRIB_RELEASE=18.04" ]; then
	toolchain_download="$swift_tag-ubuntu18.04_x86_64.tar.gz"
	elif [ $(grep RELEASE /etc/lsb-release) == "DISTRIB_RELEASE=20.04" ]; then
	toolchain_download="$swift_tag-ubuntu20.04_x86_64.tar.gz"
	else