Docker image doesn't build due to sasl

[MOZGIII]

Found in here: https://github.com/timberio/vector/pull/2702/checks?check_run_id=825720739

+ docker build --tag localhost/vector-test:test-1593592052-3ddsii19-debian target/artifacts -f distribution/docker/debian/Dockerfile
Sending build context to Docker daemon  44.69MB

Step 1/9 : FROM debian:buster-slim AS builder
buster-slim: Pulling from library/debian
8559a31e96f4: Pulling fs layer
8559a31e96f4: Verifying Checksum
8559a31e96f4: Download complete
8559a31e96f4: Pull complete
Digest: sha256:d67632d49fcae559f86bd2b685c9159d0b1e799fd1d109dfbfccfab4ea773ba5
Status: Downloaded newer image for debian:buster-slim
 ---> 43e3995ee54a
Step 2/9 : COPY vector-*.deb ./
 ---> 70422016bc7e
Step 3/9 : RUN dpkg -i vector-$(dpkg --print-architecture).deb
 ---> Running in b0d359d28690
Selecting previously unselected package vector.
(Reading database ... 6460 files and directories currently installed.)
Preparing to unpack vector-amd64.deb ...
Unpacking vector (0.10.0) ...
dpkg: dependency problems prevent configuration of vector:
 vector depends on libsasl2-2 (>= 2.1.26.dfsg1); however:
  Package libsasl2-2 is not installed.

dpkg: error processing package vector (--install):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 vector
The command '/bin/sh -c dpkg -i vector-$(dpkg --print-architecture).deb' returned a non-zero code: 1

The easiest fix is probably to add libsasl2-2 to the installation explicitly. #2928 implements this.

Although we might want to take a different route, and link to libsasl statically.

CC @fanatid