collab: Add missing dependencies for building Docker image (#17893)

This PR adds some missing dependencies to the Docker image that are now
needed in order to build collab.

When trying to build the docker image at
761129e373 it fails with the following
error:

```
985.3   = note: /usr/bin/ld: cannot find -lxkbcommon: No such file or directory
985.3           /usr/bin/ld: cannot find -lxkbcommon-x11: No such file or directory
985.3           collect2: error: ld returned 1 exit status
985.3           
985.3 
985.4 error: could not compile `collab` (bin "collab") due to 1 previous error
```

The last time we built the Docker image for collab was:

- Staging: 4f408ec65a
- Production: fc4c533d0a

Release Notes:

- N/A

Dockerfile

@@ -9,6 +9,28 @@ ARG CARGO_PROFILE_RELEASE_PANIC=abort
 ARG GITHUB_SHA
 
 ENV GITHUB_SHA=$GITHUB_SHA
+
+# At some point in the past 3 weeks, additional dependencies on `xkbcommon` and
+# `xkbcommon-x11` were introduced into collab.
+#
+# Now when we try to build collab for the Docker image, it fails with the following
+# error:
+#
+# ```
+# 985.3   = note: /usr/bin/ld: cannot find -lxkbcommon: No such file or directory
+# 985.3           /usr/bin/ld: cannot find -lxkbcommon-x11: No such file or directory
+# 985.3           collect2: error: ld returned 1 exit status
+# ```
+#
+# The last successful deploys were at:
+# - Staging: `4f408ec65a3867278322a189b4eb20f1ab51f508`
+# - Production: `fc4c533d0a8c489e5636a4249d2b52a80039fbd7`
+#
+# Installing these as a temporary workaround, but I think ideally we'd want to figure
+# out what caused them to be included in the first place.
+RUN apt-get update; \
+    apt-get install -y --no-install-recommends libxkbcommon-dev libxkbcommon-x11-dev
+
 RUN --mount=type=cache,target=./script/node_modules \
     --mount=type=cache,target=/usr/local/cargo/registry \
     --mount=type=cache,target=/usr/local/cargo/git \