Unwanted escaping of backslashes in regexes of SHACL shapes

[holycrab13]

When supplying regexes in SHACL shapes, the escape backslack needs to be escaped itself for the shape to parse correctly.
Example

<#has-version>
	...
        sh:pattern "/[a-zA-Z0-9]{4,}/[a-zA-Z0-9\\-_\\.]{3,}/[a-zA-Z0-9\\-_\\.]{3,}/[a-zA-Z0-9\\-_\\.]{3,}$" .

Desired would be single escapes

<#has-version>
	...
        sh:pattern "/[a-zA-Z0-9]{4,}/[a-zA-Z0-9\-_\.]{3,}/[a-zA-Z0-9\-_\.]{3,}/[a-zA-Z0-9\-_\.]{3,}$" .