libunwind: bump new version

libunwind/libunwind@f67ef28 adds the ability for libunwind to unwind a
stack where the return address obtained from the AARCH6 link register (x30)
has a pointer authentication code (PAC).

Needed for #7285

NO_CHANGELOG=<internal submodule version bump>
NO_DOC=<submodule version bump>
NO_TEST=<submodule version bump>

.gitmodules

@@ -59,7 +59,7 @@
 [submodule "third_party/libunwind"]
 	path = third_party/libunwind
 	url = https://github.com/tarantool/libunwind.git
-	branch = libunwind-1.6.2-tarantool
+	branch = libunwind-f67ef28-tarantool
 [submodule "third_party/tz"]
 	path = third_party/tz
 	url = https://github.com/tarantool/tz.git

libunwind @ d80afd12

-Subproject commit 3f49295a7b0b8abea7f5ec0dacbeae74e6b5e0c0
+Subproject commit d80afd12983a08eec5467824679bdcefe0977278