chore(deps): update actions/checkout action to v6.0.3 (#2183)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/checkout](https://redirect.github.com/actions/checkout) |
action | patch | `v6.0.2` → `v6.0.3` |

---

### Release Notes

<details>
<summary>actions/checkout (actions/checkout)</summary>

###
[`v6.0.3`](https://redirect.github.com/actions/checkout/blob/HEAD/CHANGELOG.md#v603)

[Compare
Source](https://redirect.github.com/actions/checkout/compare/v6.0.2...v6.0.3)

- Fix checkout init for SHA-256 repositories by
[@&#8203;yaananth](https://redirect.github.com/yaananth) in
[#&#8203;2439](https://redirect.github.com/actions/checkout/pull/2439)
- fix: expand merge commit SHA regex and add SHA-256 test cases by
[@&#8203;yaananth](https://redirect.github.com/yaananth) in
[#&#8203;2414](https://redirect.github.com/actions/checkout/pull/2414)

</details>

---

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This PR was generated by [Mend Renovate](https://mend.io/renovate/).
View the [repository job
log](https://developer.mend.io/github/prometheus/client_java).

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Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Gregor Zeitlinger <gregor.zeitlinger@grafana.com>

Author: renovate[bot]

.github/workflows/micrometer-compatibility.yml

@@ -27,7 +27,7 @@ jobs:
             # renovate: datasource=git-refs depName=zeitlinger/micrometer packageName=https://github.com/zeitlinger/micrometer currentValue=feat/prometheus-client-opt-in
             ref: 1af1b3185058941eea57dc467bfe0df5a4786fe4
     steps:
-      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
           persist-credentials: false
       - uses: jdx/mise-action@1648a7812b9aeae629881980618f079932869151 # v4.0.1