Adjust for the encodeFS/decodeFS deprecation in os-string #255

Job	Run time
arm (arm32v7)	3m 34s
darwin_arm (self-hosted, macOS, ARM64, 8.10.7)	11m 1s
arm (arm64v8)	2m 42s
build (ubuntu-latest, 8.6, 3.8.1.0)	7m 11s
darwin_arm (self-hosted, macOS, ARM64, 9.2.6)	6m 57s
build (ubuntu-latest, 8.8, 3.8.1.0)	6m 4s
freebsd (self-hosted, FreeBSD, X64, 9.4.8)	2m 7s
darwin_arm (self-hosted, macOS, ARM64, 9.4.4)	9m 12s
freebsd (self-hosted, FreeBSD, X64, 9.6.4)	2m 5s
build (ubuntu-latest, 8.10, 3.8.1.0)	6m 18s
i386	4m 11s
build (ubuntu-latest, 9.0, 3.8.1.0)	6m 31s
build (ubuntu-latest, 9.2, 3.8.1.0)	4m 44s
build (ubuntu-latest, 9.4, 3.8.1.0)	5m 4s
build (ubuntu-latest, 9.6, 3.8.1.0)	5m 52s
build (ubuntu-latest, 9.8, 3.8.1.0)	4m 7s
build (macos-12, 9.4, 3.8.1.0)	11m 33s
build (macos-12, 9.6, 3.8.1.0)	12m 58s
build (windows-latest, 9.4, 3.8.1.0)	23m 44s
build (windows-latest, 9.6, 3.8.1.0)	17m 10s
	2h 33m 5s

Provide feedback