.zip incorrectly detected as .xlsx possible regression

[eqinox76]

Expected MIME type application/zip

Returned MIME type application/vnd.openxmlformats-officedocument.spreadsheetml.sheet

Version of the library you are using v1.4.2

Output of go version go version go1.20.4 linux/amd64

Additional context Looks very much like #72. If i zip a .xlsx file without compression its still detected as excel file instead of zip. The file utility detects it fine.

$ zip -0 test2.zip Book1.xlsx 
updating: Book1.xlsx (stored 0%)
$ file test2.zip
test2.zip: Zip archive data, at least v1.0 to extract, compression method=store

Example File: https://filetransfer.io/data-package/pX0B7n1q#link (edited link)

When zipping with compression this library detects the type correctly.