build(deps): bump golang.org/x/sys from 0.3.0 to 0.4.0

Bumps [golang.org/x/sys](https://github.com/golang/sys) from 0.3.0 to 0.4.0.
- [Release notes](https://github.com/golang/sys/releases)
- [Commits](https://github.com/golang/sys/compare/v0.3.0...v0.4.0)

---
updated-dependencies:
- dependency-name: golang.org/x/sys
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/golang.org/x/sys/unix/syscall_netbsd.go

@@ -110,6 +110,20 @@ func direntNamlen(buf []byte) (uint64, bool) {
 	return readInt(buf, unsafe.Offsetof(Dirent{}.Namlen), unsafe.Sizeof(Dirent{}.Namlen))
 }
 
+func SysctlUvmexp(name string) (*Uvmexp, error) {
+	mib, err := sysctlmib(name)
+	if err != nil {
+		return nil, err
+	}
+
+	n := uintptr(SizeofUvmexp)
+	var u Uvmexp
+	if err := sysctl(mib, (*byte)(unsafe.Pointer(&u)), &n, nil, 0); err != nil {
+		return nil, err
+	}
+	return &u, nil
+}
+
 func Pipe(p []int) (err error) {
 	return Pipe2(p, 0)
 }
@@ -245,6 +259,7 @@ func Statvfs(path string, buf *Statvfs_t) (err error) {
 //sys	Chmod(path string, mode uint32) (err error)
 //sys	Chown(path string, uid int, gid int) (err error)
 //sys	Chroot(path string) (err error)
+//sys	ClockGettime(clockid int32, time *Timespec) (err error)
 //sys	Close(fd int) (err error)
 //sys	Dup(fd int) (nfd int, err error)
 //sys	Dup2(from int, to int) (err error)