Workbench: Replace mlocate with plocate.

It's been replaced in Debian.

workbench/Dockerfile

@@ -102,7 +102,6 @@ RUN apt-get update && \
         mercurial \
         meson \
         minikube \
-        mlocate \
         mongodb-database-tools \
         mythes-en-us \
         netcat-openbsd \
@@ -111,6 +110,7 @@ RUN apt-get update && \
         ostree \
         packer \
         php-cli \
+        plocate \
         podman \
         postgresql-client \
         protobuf-compiler \