ci: drop Go 1.18 from CI matrix, bump user to go 1.24

The user module now requires Go 1.24 for os.Root support.
Remove Go 1.18 from the CI test matrix.

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

Author: tonistiigi

.github/workflows/test.yml

@@ -19,7 +19,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.18.x, oldstable, stable]
+        go-version: [oldstable, stable]
         platform: [ubuntu-22.04, ubuntu-24.04, windows-2022, windows-2025, macos-15, macos-26]
     runs-on: ${{ matrix.platform }}
     timeout-minutes: 10 # guardrails timeout for the whole job
@@ -44,24 +44,6 @@ jobs:
         # We don't need to run golangci-lint here yet, but
         # there's no way to avoid it, so run it on one module.
         working-directory: ./mountinfo
-    - name: Set PACKAGES env
-      if: ${{ matrix.go-version == '1.18.x' }}
-      run: |
-        # Check if the module supports this version of Go.
-        go_version="$(go env GOVERSION)"
-        go_version="${go_version#go}"
-        
-        packages=""
-        for p in */; do
-          [ -f "$p/go.mod" ] || continue
-          if ! (cd "$p" && go list -m -f "{{if gt .GoVersion \"$go_version\"}}ko{{end}}" | grep -q ko); then
-            packages+="${p%/} "
-          else
-            echo "::notice::SKIP: github.com/moby/sys/${p%/} requires a more recent version of Go"
-          fi
-        done
-        
-        echo "PACKAGES=${packages}" >> "$GITHUB_ENV"
     - name: go mod tidy
       run: |
         make foreach CMD="go mod tidy"

user/go.mod

@@ -1,6 +1,6 @@
 module github.com/moby/sys/user
 
-go 1.18
+go 1.24
 
 require golang.org/x/sys v0.1.0
 

user/idtools_unix_test.go

@@ -5,6 +5,7 @@ package user
 import (
 	"errors"
 	"fmt"
+	"maps"
 	"os"
 	"path/filepath"
 	"testing"
@@ -292,9 +293,7 @@ func readTree(base, root string) (map[string]node, error) {
 			if err != nil {
 				return nil, err
 			}
-			for path, nodeinfo := range subtree {
-				tree[path] = nodeinfo
-			}
+			maps.Copy(tree, subtree)
 		}
 	}
 	return tree, nil

user/user.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"slices"
 	"strconv"
 	"strings"
 )
@@ -373,12 +374,7 @@ func GetExecUser(userSpec string, defaults *ExecUser, passwd, group io.Reader) (
 			// If the group argument isn't explicit, we'll just search for it.
 			if groupArg == "" {
 				// Check if user is a member of this group.
-				for _, u := range g.List {
-					if u == matchedUserName {
-						return true
-					}
-				}
-				return false
+				return slices.Contains(g.List, matchedUserName)
 			}
 
 			if gidErr == nil {