mkosi: Update to latest

Configuration now takes priority over CLI options so we have to
configure the defaults for settings that we want to allow overriding
from the CLI. We also explicitly set some other settings so that they
can't be overridden from the CLI anymore. For example the base and
initrd image should never be made bootable so we set Bootable=no
explicitly for both.

.github/workflows/mkosi.yml

@@ -76,29 +76,31 @@ jobs:
 
     steps:
     - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744
-    - uses: systemd/mkosi@0af3f8a35c3be0e54b20234be7ab478d25bcc740
+    - uses: systemd/mkosi@cb5974d013f7c4c2a45f67c9ae990767e32e9034
 
     - name: Configure
       run: |
+        # We configure ExtraSearchPaths=build/ so make sure build/ exists.
+        mkdir build/
+
         tee mkosi.conf <<- EOF
         [Distribution]
         Distribution=${{ matrix.distro }}
         Release=${{ matrix.release }}
+        EOF
 
+        tee mkosi.conf.d/99-ci.conf <<- EOF
         [Content]
         Environment=CI_BUILD=1
                     SLOW_TESTS=true
 
-        [Output]
+        [Host]
         KernelCommandLineExtra=systemd.unit=mkosi-check-and-shutdown.service
                                systemd.journald.max_level_console=debug
                                # udev's debug log output is very verbose, so up it to info in CI.
                                udev.log_level=info
                                # Root device can take a long time to appear, so let's bump the timeout.
                                systemd.default_device_timeout_sec=180
-
-        [Host]
-        ExtraSearchPaths=!*
         QemuVsock=yes
         Ephemeral=yes
         EOF