chore(deps): update docker/dockerfile docker tag to v1.18 (#4)

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This PR contains the following updates:

| Package | Type | Update | Change | OpenSSF |
|---|---|---|---|---|
| [docker/dockerfile](https://redirect.github.com/moby/buildkit) |
syntax | minor | `1.7` -> `1.18` | [![OpenSSF
Scorecard](https://api.securityscorecards.dev/projects/github.com/moby/buildkit/badge)](https://securityscorecards.dev/viewer/?uri=github.com/moby/buildkit)
|

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Dockerfile

@@ -1,4 +1,4 @@
-# syntax=docker/dockerfile:1.7
+# syntax=docker/dockerfile:1.18
 
 FROM oven/bun:1.2.22-debian AS builder
 WORKDIR /app