Build jfrog-cli as single binary to avoid linker errors

By default, Go bitbake recipes use the linkshared flag to link binaries to the runtime. It's not clear exactly what changed between 1.19 and 1.20 but this seems to cause a problem with this recipe. Note that this flag is described in the Go documentation as experimental (https://pkg.go.dev/cmd/link#hdr-Command_Line)

Set GO_LINKSHARED to "" to remove this flag and build jfrog-cli as a self contained executable.

If required, this change can be reverted if the linker issue is resolved first.