Unbreak source distribution tarball construction. (JuliaLang#43096)

Co-authored-by: Jameson Nash <[email protected]>

Author: 2 people

Makefile

@@ -456,6 +456,10 @@ endif
 	-ls stdlib/srccache/*.tar.gz >> light-source-dist.tmp
 	-ls stdlib/*/StdlibArtifacts.toml >> light-source-dist.tmp
 
+	# Include all git-tracked filenames
+	git ls-files >> light-source-dist.tmp
+	
+	# Include documentation filenames
 	find doc/_build/html >> light-source-dist.tmp
 
 # Make tarball with only Julia code + stdlib tarballs