chore(deps): update docker.io/library/golang docker tag to v1.21.6

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
docker.io/library/golang	stage	patch	1.21.5-alpine -> 1.21.6-alpine

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[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (eb11d6d) 58.92% compared to head (ac11ac8) 58.92%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #370 +/- ## ======================================= Coverage 58.92% 58.92% ======================================= Files 30 30 Lines 1816 1816 ======================================= Hits 1070 1070 Misses 650 650 Partials 96 96 ```

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