clang-format: reformat code with clang-format 15.0.4-1.fc37

This is the version shipped in Fedora 37. As Fedora 37 is now out, the
core developers switch to it. Our gitlab-ci will also use that as base
image for the check-{patch.tree} tests and to generate the pages. There
is a need that everybody agrees on which clang-format version to use,
and that version should be the one of the currently used Fedora release.

Also update the used Fedora image in "contrib/scripts/nm-code-format-container.sh"
script.

The gitlab-ci still needs update in the following commit. The change
in isolation will break the "check-tree" test.

contrib/scripts/nm-code-format-container.sh

@@ -10,7 +10,7 @@ die() {
 DIR="$(realpath "$(dirname "$0")/../../")"
 cd "$DIR"
 
-FEDORA_VERSION=36
+FEDORA_VERSION=37
 
 PODNAME="nm-code-format-f$FEDORA_VERSION"