Enable gofumpt extra rules

Commit b2f8a74d "clothed" the naked return as inflicted by gofumpt
v0.9.0. Since gofumpt v0.9.2 this rule was moved to "extra" category,
not enabled by default. The only other "extra" rule is to group adjacent
parameters with the same type, which also makes sense.

Enable gofumpt "extra" rules, and reformat the code accordingly.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

internal/linux/linux.go

@@ -15,7 +15,7 @@ func Dup3(oldfd, newfd, flags int) error {
 }
 
 // Exec wraps [unix.Exec].
-func Exec(cmd string, args []string, env []string) error {
+func Exec(cmd string, args, env []string) error {
 	err := retryOnEINTR(func() error {
 		return unix.Exec(cmd, args, env)
 	})