b/ci: update build container to Fedora 35

Fedora 32 is EOL since over half a year, update to the current stable
Fedora release.

toolchains: adds clang as it's no longer part of the llvm package,
changes toolchain path references to GCC 11, and rebuilds the sysroot.

edk2: update to latest stable (old version cannot build with a newer
minor version of Python 3) and patch to disable -Werror and make the
newer included Brotli version work as it natively includes BUILD
files which need to be patched out to make the source files accessible.

linux: add patch to fix PVH ELF note entrypoint with binutils 2.32+ as
otherwise the .notes section gets emitted with broken alignment.

m/t/launch: RunMicroVM is broken if SerialPort is not set with newer
QEMU versions because fcntl(2) fails to interact with a broken file
descriptor. This is due to a confusion between nil interfaces and
interfaces containing a nil pointer causing Go to improperly pass the
file descriptor. Changing the type of SerialPort to the actual
interface resolves the issue.

Change-Id: I03a8cbf4f80a7363794dad1ff62ccb57e778cac3
Reviewed-on: https://review.monogon.dev/c/monogon/+/529
Reviewed-by: Leopold Schabel <leo@nexantic.com>
diff --git a/third_party/linux/external.bzl b/third_party/linux/external.bzl
index 04a0826..9f0a0b0 100644
--- a/third_party/linux/external.bzl
+++ b/third_party/linux/external.bzl
@@ -29,6 +29,7 @@
         patch_args = ["-p1"],
         patches = [
             "//third_party/linux/external:0001-block-partition-expose-PARTUUID-through-uevent.patch",
+            "//third_party/linux/external:discard-gnu-note-section.patch",
         ],
         sha256 = sums[version],
         strip_prefix = "linux-" + version,