build(deps): bump rollkit/gm

Bumps the patch-updates group with 1 update in the /docker directory: [rollkit/gm](https://github.com/rollkit/gm).


Updates `rollkit/gm` from v0.1.0 to v0.3.1
- [Release notes](https://github.com/rollkit/gm/releases)
- [Commits](v0.1.0...v0.3.1)

---
updated-dependencies:
- dependency-name: rollkit/gm
  dependency-type: direct:production
  dependency-group: patch-updates
...

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

docker/Dockerfile

@@ -1,4 +1,4 @@
-FROM ghcr.io/rollkit/gm:v0.1.0
+FROM ghcr.io/rollkit/gm:v0.3.1
 
 USER root