Change PDF load Get Info on PDF to readonly (#3254)

# Description of Changes

Please provide a summary of the changes, including:

- Fixed the behavior, that the metadata of a pdf was changed when using
the "Get info on PDF" function. Notably the Producer and
ModificationDate are updated currently, wich is not in line with the
description "Get Info".

---

## Checklist

### General

- [x] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [x] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md)
(if applicable)
- [x] I have performed a self-review of my own code
- [x] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [x] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md#6-testing)
for more details.

Co-authored-by: maxi322 <maxi322@users.noreply.github.com>

src/main/java/stirling/software/SPDF/controller/api/security/GetInfoOnPDF.java

@@ -126,7 +126,8 @@ public class GetInfoOnPDF {
     @Operation(summary = "Summary here", description = "desc. Input:PDF Output:JSON Type:SISO")
     public ResponseEntity<byte[]> getPdfInfo(@ModelAttribute PDFFile request) throws IOException {
         MultipartFile inputFile = request.getFileInput();
-        try (PDDocument pdfBoxDoc = pdfDocumentFactory.load(inputFile); ) {
+        boolean readonly = true;
+        try (PDDocument pdfBoxDoc = pdfDocumentFactory.load(inputFile, readonly); ) {
             ObjectMapper objectMapper = new ObjectMapper();
             ObjectNode jsonOutput = objectMapper.createObjectNode();