Test error 

````
[smoke] > quarto render docs\project\site -o - => ./test.ts:121:72
error: AssertionError: Failed assertion:

--------------------------------------------------------------------------------
[smoke] > quarto render docs\project\site -o -
          run-tests.psl ..\..\..\..\..\..\C:\Users\chris\Documents\DEV_R\quarto-cli\tests\smoke\project\project-stdout.test.ts

[verify] > unknown

La syntaxe du nom de fichier, de répertoire ou de volume est incorrecte. (os error 123), stat 'C:\Users\chris\Documents\DEV_R\quarto-cli\tests\docs\project\site\C:\Users\chris\AppData\Local\Temp\quarto-session96c8468e\9b1cbc71\dc6b9af2_files'
Error: La syntaxe du nom de fichier, de répertoire ou de volume est incorrecte. (os error 123), stat 'C:\Users\chris\Documents\DEV_R\quarto-cli\tests\docs\project\site\C:\Users\chris\AppData\Local\Temp\quarto-session96c8468e\9b1cbc71\dc6b9af2_files'
    at Object.lstatSync (deno:runtime/js/30_fs.js:305:9)
    at existsSync (file:///C:/Users/chris/Documents/DEV_R/quarto-cli/src/vendor/deno.land/std@0.166.0/fs/exists.ts:75:10)
    at removeIfEmptyDir (file:///C:/Users/chris/Documents/DEV_R/quarto-cli/src/core/path.ts:47:7)
    at renderProject (file:///C:/Users/chris/Documents/DEV_R/quarto-cli/src/command/render/project.ts:347:9)
    at async Command.fn (file:///C:/Users/chris/Documents/DEV_R/quarto-cli/src/command/render/cmd.ts:193:26)
    at async Command.execute (file:///C:/Users/chris/Documents/DEV_R/quarto-cli/src/vendor/deno.land/x/cliffy@v0.25.4/command/command.ts:1790:7)
    at async quarto (file:///C:/Users/chris/Documents/DEV_R/quarto-cli/src/quarto.ts:111:3)
    at async Object.execute (file:///C:/Users/chris/Documents/DEV_R/quarto-cli/tests/test.ts:68:5)
    at async fn (file:///C:/Users/chris/Documents/DEV_R/quarto-cli/tests/test.ts:165:11)
    at async Object.testStepSanitizer [as fn] (deno:cli/js/40_testing.js:448:7)
````

That is definitely not correctly build 
````
C:\Users\chris\Documents\DEV_R\quarto-cli\tests\docs\project\site\C:\Users\chris\AppData\Local\Temp\quarto-session96c8468e\9b1cbc71\dc6b9af2_files
````

It comes from 
https://github.com/quarto-dev/quarto-cli/blob/9ce89221b1ac4f36a0826c8a9778b9e60b045f66/src/command/render/project.ts#L305-L312

If I had some log info 
````
      if (!keepFiles) {
        console.log(projDir);
        console.log(renderedFile.file);
        console.log(dirname(renderedFile.file));
        console.log(inputFilesDir(renderedFile.file));
````
this is the result
````
C:\Users\chris\Documents\DEV_R\quarto-cli\tests\docs\project\site
C:\Users\chris\AppData\Local\Temp\quarto-session96c8468e\9b1cbc71\dc6b9af2.html
C:\Users\chris\AppData\Local\Temp\quarto-session96c8468e\9b1cbc71
dc6b9af2_files
````

Definitely not right 
 
cscheid
2023-02-02T18:15:57Z
cderv
bug
v1.4
open
Removing empty dir is not working as wrong path is created (when outputing to stdout)
https://github.com/quarto-dev/quarto-cli/issues/4194