Remove obsolete Go-version-based alternatives

Since utils requires Go 1.23, code specifically for older versions is
no longer necessary.

Signed-off-by: Stephen Kitt <skitt@redhat.com>

Author: skitt

exec/exec.go

@@ -18,6 +18,7 @@ package exec
 
 import (
 	"context"
+	"errors"
 	"io"
 	"io/fs"
 	osexec "os/exec"
@@ -97,6 +98,21 @@ func New() Interface {
 	return &executor{}
 }
 
+// maskErrDotCmd reverts the behavior of osexec.Cmd to what it was before go1.19
+// specifically set the Err field to nil (LookPath returns a new error when the file
+// is resolved to the current directory.
+func maskErrDotCmd(cmd *osexec.Cmd) *osexec.Cmd {
+	cmd.Err = maskErrDot(cmd.Err)
+	return cmd
+}
+
+func maskErrDot(err error) error {
+	if err != nil && errors.Is(err, osexec.ErrDot) {
+		return nil
+	}
+	return err
+}
+
 // Command is part of the Interface interface.
 func (executor *executor) Command(cmd string, args ...string) Cmd {
 	return (*cmdWrapper)(maskErrDotCmd(osexec.Command(cmd, args...)))

exec/fixup_go118.go

@@ -34,6 +34,14 @@ func New[E ordered](items ...E) Set[E] {
 	return ss
 }
 
+// Clear empties the set.
+// It is preferable to replace the set with a newly constructed set,
+// but not all callers can do that (when there are other references to the map).
+func (s Set[T]) Clear() Set[T] {
+	clear(s)
+	return s
+}
+
 // KeySet creates a Set[E] from a keys of a map[E](? extends interface{}).
 func KeySet[E ordered, A any](theMap map[E]A) Set[E] {
 	ret := Set[E]{}