feat(io): Remove execute permission from a saved file (#37)

<!-- markdownlint-disable MD041 -->

**Issue:** close #29

### Checklist

- [x] This Pull Request introduces a new feature.
- [ ] This Pull Request fixes a bug.

### Description

Since I specified as `os.ModePerm`, all permission was added.

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- [x] I agree to follow the [Code of
Conduct](https://github.com/5ouma/mli/blob/main/.github/CODE_OF_CONDUCT.md).

Signed-off-by: Souma <[email protected]>

lib/io.go

@@ -16,7 +16,7 @@ func (loginItems *LoginItems) Save(path string, force bool) error {
 	if err != nil {
 		return err
 	}
-	if err := os.WriteFile(path, append(data, 10), os.ModePerm); err != nil {
+	if err := os.WriteFile(path, append(data, 10), 0644); err != nil {
 		return err
 	}