Add changelog entry for workflows

docs/devel/changelog_staging.md

@@ -8,3 +8,4 @@
 - Fixed blunder in `PdfImage.extract()` producing an incorrect output path for prefixes containing a dot. In the `extract-images` CLI, this caused all output images of a type to be written to the same path for a document containing a non-extension dot in the filename.
 - XFA / rendering CLI: Fixed incorrect recognition of document length. `pdf.init_forms()` must be called before `len(pdf)`.
 - Made `get_text_range()` allocation adapt to pdfium version, as `FPDFText_GetText()` has been reverted to UCS-2. (See v4.28 changelog for background.)
+- Updated workflows to include both `macos-13` and `macos-14` in test matrices because v13 is Intel and v14 ARM64 on GH actions. Removed python 3.7 testing because not supported anymore on `macos-14` runners.