chore: modernize the codebase using go 1.26 (#278)

This runs:

```
go run golang.org/x/tools/gopls/internal/analysis/modernize/cmd/modernize@latest -fix ./...
```

over the codebase, as this is using go 1.26, it can also use the new
new() functionallity so AsPtr and boolPtr is are needed anymore.

Signed-off-by: Miek Gieben <miek@miek.nl>

internal/machine/firewall/iptables_linux.go

@@ -103,7 +103,7 @@ func createIptablesChains() error {
 			}
 
 			firstRejectRuleNum := 0
-			for _, line := range strings.Split(string(out), "\n") {
+			for line := range strings.SplitSeq(string(out), "\n") {
 				fields := strings.Fields(line)
 				if len(fields) < 2 {
 					continue