Revert "archive: honor tar.umask even for pax headers"

This reverts commit 10f343ea814f5c18a0913997904ee11cd9b7da24, whose
output is no longer bit-for-bit equivalent from the older versions
of Git, which the infrastructure to (pretend to) upload tarballs
kernel.org uses depends on.
diff --git a/archive-tar.c b/archive-tar.c
index df2f4c8..0d1e6bd 100644
--- a/archive-tar.c
+++ b/archive-tar.c
@@ -192,7 +192,7 @@
 	unsigned int mode;
 	memset(&header, 0, sizeof(header));
 	*header.typeflag = TYPEFLAG_EXT_HEADER;
-	mode = 0100666 & ~tar_umask;
+	mode = 0100666;
 	sprintf(header.name, "%s.paxheader", sha1_to_hex(sha1));
 	prepare_header(args, &header, mode, size);
 	write_blocked(&header, sizeof(header));
@@ -300,7 +300,7 @@
 	strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
 	memset(&header, 0, sizeof(header));
 	*header.typeflag = TYPEFLAG_GLOBAL_HEADER;
-	mode = 0100666 & ~tar_umask;
+	mode = 0100666;
 	strcpy(header.name, "pax_global_header");
 	prepare_header(args, &header, mode, ext_header.len);
 	write_blocked(&header, sizeof(header));