Spatie\PdfToText\Exceptions\CouldNotExtractText
You're mixing Unix style paths and Windows style paths.
Windows uses back slashes \ and Unix uses forward slashes / to separate folders.
Change $newPDF from cv/php1A57.tmp.pdf to cv\php1A57.tmp.pdf
You'll also need to make sure you've installed pdftotext. This answer suggests downloading it from here.
As the answer also suggests, you'll need to change the path to the pdftotext binary like this:
$text = (new Pdf('Path\to\pdftotext.exe'))
->setPdf(public_path('cv'), $newPDF)
->text();