Update golang Docker tag to v1.26 (#198)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| golang | stage | minor | `1.25` → `1.26` |

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Dockerfile

@@ -1,4 +1,4 @@
-ARG go_version=1.25
+ARG go_version=1.26
 
 # development
 FROM golang:${go_version} AS development