Add support for EL10

* Upadate dev container to use EL10
* Update CI to use EL10
* Update spec file for EL10
* Add `make rpm` target for building RPMs
* Use `mktemp` for `make dist` to use devcontainer filesystem
* Set default dhcpd and tftpd to dnsmasq for EL10
* Fix dnsmasq template tftp paths to use basename

Signed-off-by: Timothy Middelkoop <tmiddelkoop@internet2.edu>

.devcontainer/devcontainer.json

@@ -1,6 +1,6 @@
 {
   "name": "Warewulf Development",
-  "image": "registry.docker.com/library/rockylinux:9",
+  "image": "registry.docker.com/rockylinux/rockylinux:10",
   "remoteUser": "vscode",
   "onCreateCommand": "sudo dnf install -y dnf-utils && sudo dnf config-manager --set-enabled crb && sudo dnf install -y unzip cpio gpgme-devel python3-sphinx python3-sphinx_rtd_theme",
   "features": {