Bump the build-deps group in /build/deps with 4 updates

Bumps the build-deps group in /build/deps with 4 updates: davidanson/markdownlint-cli2, [ferretdb/legacy-mongo-shell](https://github.com/FerretDB/deps), mongo and postgres.


Updates `davidanson/markdownlint-cli2` from v0.8.1 to v0.10.0

Updates `ferretdb/legacy-mongo-shell` from 6.0.8-1 to 7.0.2-1
- [Commits](https://github.com/FerretDB/deps/commits)

Updates `mongo` from 6.0.8 to 7.0.2

Updates `postgres` from 15.3 to 16.0

---
updated-dependencies:
- dependency-name: davidanson/markdownlint-cli2
  dependency-type: direct:production
  dependency-group: build-deps
- dependency-name: ferretdb/legacy-mongo-shell
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: build-deps
- dependency-name: mongo
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: build-deps
- dependency-name: postgres
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: build-deps
...

Signed-off-by: dependabot[bot] <[email protected]>

build/deps/markdownlint.Dockerfile

@@ -1 +1 @@
-FROM davidanson/markdownlint-cli2:v0.8.1
+FROM davidanson/markdownlint-cli2:v0.10.0

build/deps/mongo.Dockerfile

@@ -1 +1 @@
-FROM ghcr.io/ferretdb/legacy-mongo-shell:6.0.8-1
+FROM ghcr.io/ferretdb/legacy-mongo-shell:7.0.2-1

build/deps/mongo6.Dockerfile

@@ -1 +1 @@
-FROM mongo:6.0.8
+FROM mongo:7.0.2

build/deps/postgres.Dockerfile

@@ -1 +1 @@
-FROM postgres:15.3
+FROM postgres:16.0