chore: Remove tests from final zip file (#207)

* Remove tests from final zip file

* chore: Add comment to .gitattributes about export-ignore

---------

Co-authored-by: Fabian Meyer <3982806+meyfa@users.noreply.github.com>

Author: shyim

.gitattributes

@@ -1,2 +1,6 @@
 # Auto detect text files and perform LF normalization
 * text=auto
+
+# Remove unnecessary files from Composer package
+/.github/ export-ignore
+/tests/ export-ignore