keventd: record the libblkid build requirement

keventd is the only thing in the tree that links libblkid, so a tree
that used to build now stops in configure with no hint of which package
to install.  Say so where people look for dependencies, and give CI the
package it now needs.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

.github/workflows/weekly.yml

@@ -34,7 +34,7 @@ jobs:
       - name: Install dependencies
         run: |
           sudo apt-get -y update
-          sudo apt-get -y install pkg-config jq libcap-dev libconfuse-dev
+          sudo apt-get -y install pkg-config jq libcap-dev libconfuse-dev libblkid-dev
           wget https://github.com/troglobit/libuev/releases/download/v2.4.1/libuev-2.4.1.tar.xz
           wget https://github.com/troglobit/libite/releases/download/v2.6.2/libite-2.6.2.tar.gz
           tar xf libuev-2.4.1.tar.xz