Update earthly/dind Docker tag to ubuntu-20.04-docker-27.1.2-1 (#105)

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This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| earthly/dind | patch | `ubuntu-20.04-docker-27.1.1-1` ->
`ubuntu-20.04-docker-27.1.2-1` |

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docs/dockerhub.md

@@ -12,7 +12,7 @@ This image supports 3 Linux distributions:
 
 For which the current latest tags (respectively) are:
 * `alpine-3.20-docker-26.1.5-r0`
-* `ubuntu-20.04-docker-27.1.1-1`
+* `ubuntu-20.04-docker-27.1.2-1`
 * `ubuntu-23.04-docker-25.0.2-1`
 * `ubuntu-24.04-docker-27.1.1-1`