Move to typical go project layout, fix golangci-lint warnings, update deps

vendor/github.com/tklauser/go-sysconf/.cirrus.yml

@@ -1,6 +1,6 @@
 env:
   CIRRUS_CLONE_DEPTH: 1
-  GO_VERSION: go1.21.3
+  GO_VERSION: go1.20
 
 freebsd_12_task:
   freebsd_instance:

vendor/github.com/tklauser/go-sysconf/sysconf_linux.go

@@ -6,6 +6,7 @@ package sysconf
 
 import (
 	"bufio"
+	"io/ioutil"
 	"os"
 	"runtime"
 	"strconv"
@@ -25,7 +26,7 @@ const (
 )
 
 func readProcFsInt64(path string, fallback int64) int64 {
-	data, err := os.ReadFile(path)
+	data, err := ioutil.ReadFile(path)
 	if err != nil {
 		return fallback
 	}
@@ -85,16 +86,10 @@ func getNprocsProcStat() (int64, error) {
 	s := bufio.NewScanner(f)
 	for s.Scan() {
 		if line := strings.TrimSpace(s.Text()); strings.HasPrefix(line, "cpu") {
-			cpu, _, found := strings.Cut(line, " ")
-			if found {
-				// skip first line with accumulated values
-				if cpu == "cpu" {
-					continue
-				}
-				_, err := strconv.ParseInt(cpu[len("cpu"):], 10, 64)
-				if err == nil {
-					count++
-				}
+			l := strings.SplitN(line, " ", 2)
+			_, err := strconv.ParseInt(l[0][3:], 10, 64)
+			if err == nil {
+				count++
 			}
 		} else {
 			// The current format of /proc/stat has all the
@@ -103,9 +98,6 @@ func getNprocsProcStat() (int64, error) {
 			break
 		}
 	}
-	if err := s.Err(); err != nil {
-		return -1, err
-	}
 	return count, nil
 }
 

vendor/github.com/tklauser/go-sysconf/sysconf_netbsd.go

@@ -25,10 +25,10 @@ const (
 	_POSIX2_UPE       = -1
 )
 
-var clktck struct {
-	sync.Once
-	v int64
-}
+var (
+	clktck     int64
+	clktckOnce sync.Once
+)
 
 func sysconfPOSIX(name int) (int64, error) {
 	// NetBSD does not define all _POSIX_* values used in sysconf_posix.go
@@ -42,6 +42,7 @@ func sysconf(name int) (int64, error) {
 	// Duplicate the relevant values here.
 
 	switch name {
+
 	// 1003.1
 	case SC_ARG_MAX:
 		return sysctl32("kern.argmax"), nil
@@ -54,14 +55,13 @@ func sysconf(name int) (int64, error) {
 		}
 		return -1, nil
 	case SC_CLK_TCK:
-		// TODO: use sync.OnceValue once Go 1.21 is the minimal supported version
-		clktck.Do(func() {
-			clktck.v = -1
+		clktckOnce.Do(func() {
+			clktck = -1
 			if ci, err := unix.SysctlClockinfo("kern.clockrate"); err == nil {
-				clktck.v = int64(ci.Hz)
+				clktck = int64(ci.Hz)
 			}
 		})
-		return clktck.v, nil
+		return clktck, nil
 	case SC_NGROUPS_MAX:
 		return sysctl32("kern.ngroups"), nil
 	case SC_JOB_CONTROL: