Don't add code annotation post processor for PDF when deactivated

[cderv]

fix #6320

See detailled analysis in #6320 (comment)

I believe we need to avoid adding the post processor for LaTeX when code-annotations: false because we won't do any Lua processing in that case

quarto-cli/src/resources/filters/quarto-pre/code-annotation.lua

Lines 511 to 524 in 49f1bd1

	-- return code_filter
	return {
	Pandoc = function(doc)
	local codeAnnotations = param(constants.kCodeAnnotationsParam)
	-- if code annotations is false, then don't even walk it
	if codeAnnotations == false then
	return nil
	end
	return _quarto.ast.walk(doc, code_filter)
	end
	}
	end

[cderv]

From @mcanouil comment in #6316 (comment) it seems the we don't get the expected result when code-annotations: none as

---
format:
  pdf:
    code-annotations: none
---

```r
1 + 1 # <1>
2 + 2 
```

1. A comment

gets me

• Post processor does happen and add the \circled command
• But Lua filter runs and correctly insert the preamble

It seems like this should also be fixed... 🤔

[cderv]

About my last comment, I opened a new issue to keep things scoped.

• Annotation processing in LaTeX does not respect none  #6332

This means this PR is only about fixing code-annotations: false