[BUG] extra empty lines added by yaml serializer on multiline values

Description

When using yaml serializer on multiline values, it doubled every line break, leading to extra empty lines

Setup

Pillar:

mytest:
  value1: "foobar"
  value2: 42
  value3: |
    multiline
    string

State:

mytest:
  file.serialize:
    - name: /tmp/mytest
    - user: root
    - group: root
    - mode: "0644"
    - dataset_pillar: mytest
    - formatter: yaml

created file /tmp/mytest:

# cat /tmp/mytest 
value1: foobar
value2: 42
value3: 'multiline

  string

  '

also able to reproduce with:

# salt-call slsutil.serialize yaml obj='{some: "multiline\nstring"}'
local:
    {some: 'multiline

        string'}

Please be as specific as possible and give set-up details.

[x] on-prem machine
[ ] VM (Virtualbox, KVM, etc. please specify)
[ ] VM running on a cloud service, please be explicit and add details
[ ] container (Kubernetes, Docker, containerd, etc. please specify)
[ ] or a combination, please be explicit
[ ] jails if it is FreeBSD
[ ] classic packaging
[x] onedir packaging
[ ] used bootstrap to install

Steps to Reproduce the behavior

# salt-call slsutil.serialize yaml obj='{some: "multiline\nstring"}'
local:
    {some: 'multiline

        string'}

Expected behavior

# salt-call slsutil.serialize yaml obj='{some: "multiline\nstring"}'
local:
    {some: 'multiline    
        string'}

Versions Report

salt --versions-report

(Provided by running salt --versions-report. Please also mention any differences in master/minion versions.) ```yaml # salt-call -V Salt Version: Salt: 3005.1 Dependency Versions: cffi: 1.14.6 cherrypy: 18.6.1 dateutil: 2.8.1 docker-py: Not Installed gitdb: Not Installed gitpython: Not Installed Jinja2: 3.1.0 libgit2: Not Installed M2Crypto: Not Installed Mako: Not Installed msgpack: 1.0.2 msgpack-pure: Not Installed mysql-python: Not Installed pycparser: 2.21 pycrypto: Not Installed pycryptodome: 3.9.8 pygit2: Not Installed Python: 3.9.16 (main, Jan 6 2023, 22:50:03) python-gnupg: 0.4.8 PyYAML: 5.4.1 PyZMQ: 23.2.0 smmap: Not Installed timelib: 0.2.4 Tornado: 4.5.3 ZMQ: 4.3.4 System Versions: dist: debian 10 buster locale: utf-8 machine: x86_64 release: 4.19.0-24-cloud-amd64 system: Linux version: Debian GNU/Linux 10 buster ```

saltstack / salt

[BUG] extra empty lines added by yaml serializer on multiline values #65598