Line breaks are rendered as <br> and not <br/> in the resulting svg file, resulting in parsing errors for external svg parsers

Describe the bug Line breaks are rendered as <br> and not <br/> in the resulting svg file, resulting in parsing errors for external svg parsers

To Reproduce Render the diagram

graph TD
    F[Line break `<br/>` Line 2] --> R

<br/> gets rendered as <br>

Expected behavior <br/> and <br> and <br /> should get rendered as <br/> to be valid xml and parse correctly in more parsers.

[knsv]

What a silly problem. We must fix this.

[titibandit]

rendering my graph

graph TB
    F{the line <br/> after breaking} --> R

using

{
  "flowchart": {
    "htmlLabels": false
  }
}

as a config file works! Line breaks are now rendered. I use mermaid-cli to generate my chart, and view the resulting SVGs in Firefox.