Bump github.com/sagernet/sing from 0.5.1 to 0.7.6 #34

Job	Run time
check-assets	6s
build (openbsd, amd64)	47s
build (freebsd, amd64)	59s
build (windows, amd64)	52s
build (linux, 386)	58s
build (windows, 386)	56s
build (openbsd, 386)	58s
build (freebsd, 386)	55s
build (linux, arm, 6)	43s
build (linux, amd64)	44s
build (darwin, amd64)	1m 4s
build (linux, arm, 5)	44s
build (darwin, arm64)	56s
build (windows, arm64)	54s
build (android, amd64, android-amd64)	1m 8s
build (linux, loong64)	47s
build (linux, mips64)	58s
build (linux, arm64)	48s
build (android, arm64)	1m 17s
build (linux, mipsle)	1m 27s
build (windows, arm, 7)	52s
build (linux, mips)	1m 27s
build (linux, mips64le)	55s
build (linux, riscv64)	52s
build (freebsd, arm64)	53s
build (openbsd, arm, 7)	50s
build (linux, ppc64le)	49s
build (linux, arm, 7)	50s
build (linux, s390x)	47s
build (linux, ppc64)	48s
build (freebsd, arm, 7)	54s
build (openbsd, arm64)	1m 0s
	28m 58s

Provide feedback