Exclude folders from NetBeans PHP code analysis

### Apache NetBeans version

Apache NetBeans 15 release candidate

### What happened

I've been using Net Beans for PHP development at work, and found that the code analyzer detects errors in some of the free libraries we use, which in turn causes the project to be marked as having errors (Red exclamation mark on the Projects browser).

Since we do not mantain these libraries, I added them to the Project Properties -> Ignored Folders -> Extra Folders for Code Analysis settings of my current project (I don't want to exclude them from the project, since we use the autocomplete/intellisense feature of the IDE), but this had no visible effect: The files are still marked as having an error, as well as the project.

Am I using the code analyzer exclusions feature wrongly? Is there any way to have the selected folders excluded from error checking but still have them visible within the project?

### How to reproduce

_No response_

### Did this work correctly in an earlier version?

Apache NetBeans 12.3 or earlier

### Operating System

Windowns 10

### JDK

Java: 10.0.1; Java HotSpot(TM) 64-Bit Server VM 10.0.1+10

### Apache NetBeans packaging

Apache NetBeans provided installer

### Anything else

I have also found the same question on StackOverflow, they said that the feature is broken Since updating to 8.0

https://stackoverflow.com/questions/24740604/exclude-folders-from-net-beans-8-php-code-analysis

### Are you willing to submit a pull request?

No

### Code of Conduct

Yes

No source file, test, or entry point is identified; start by reproducing the PHP project behavior in NetBeans 15 with an ignored library folder and compare it with NetBeans 12.3, also reviewing the linked Stack Overflow report. Done means ignored folders remain visible for autocomplete while their analyzer errors no longer mark files or the project.

Written by the indexing model from the issue text.