Falsy unsaved changes message

[yuri-g-taboola]

Describe the bug
The Unsaved changes message appears when you edit and revert the changes.

To Reproduce

1. configure the CMS to work with gihub backend
2. start the cms
3. create a new post and save it
4. make a change and revert it
5. The Unsaved Changes doesn't change to Changes Saved

Expected behavior
The Unsaved Changes should be replaced with Changes Saved

Screenshots

Applicable Versions:

• Decap CMS version: 3.3.2
• Git provider: GitHub
• OS: Mac OS Sonoma 14.4
• Browser version Firefox 129

• Node.JS version: 20.12.2

CMS configuration
https://github.com/decaporg/decap-cms/blob/main/dev-test/config.yml
with gitthub backend

Additional context

It seems like the issue has been introduced by adding a new line in packages/decap-cms-core/src/backend.ts#entryToRaw method

    let content = format.toFile(entry.get('data').toJS(), fieldsOrder, fieldsComments);
    if (content.slice(-1) != '\n') {
      // add the EOL if it does not exist.
      content += '\n';
    }
    return content;
  }

in #7039 while solving #1382
The addition of the newline is conflicting with the trimming the end of content in markdown widget at https://github.com/decaporg/decap-cms/blob/main/packages/decap-cms-widget-markdown/src/serializers/index.js#L151

  /**
   * Return markdown with trailing whitespace removed.
   */
  return trimEnd(markdown);

[martinjagodic]

This is quite a dilemma. return trimEnd(markdown); appears to be there with a reason (introduced in #653), so we should be careful how we approach this.

[LHSnow]

Possibly related to #7142?

[yuri-g-taboola]

@martinjagodic
I think the by the book solution will be to add the new line in #7093 only for json files.