ci: install kmod for mkosi depmod

After installing the kernel package into the live image, mkosi runs
depmod on the host against the image's module tree. depmod ships in
the kmod package, which isn't in the runner container by default.

.gitea/workflows/e2e.yml

@@ -37,7 +37,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends \
             mkosi debootstrap squashfs-tools \
-            systemd-ukify systemd-boot \
+            systemd-ukify systemd-boot kmod \
             debian-archive-keyring \
             qemu-system-x86 qemu-utils \
             dnsmasq iperf3 ipxe-qemu

.gitea/workflows/release.yml

@@ -34,7 +34,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends \
             mkosi debootstrap squashfs-tools dosfstools \
-            systemd-ukify systemd-boot \
+            systemd-ukify systemd-boot kmod \
             debian-archive-keyring
 
       - name: Install templ