Update docker.io/golang Docker tag to v1.21.4 (#2828)

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This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| docker.io/golang | patch | `1.21.3` -> `1.21.4` |

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Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.woodpecker/binaries.yml

@@ -9,7 +9,7 @@ when:
   event: tag
 
 variables:
-  - &golang_image 'docker.io/golang:1.21.3'
+  - &golang_image 'docker.io/golang:1.21.4'
   - &node_image 'docker.io/node:21-alpine'
   - &xgo_image 'docker.io/techknowlogick/xgo:go-1.21.4'
   - &xgo_version 'go-1.21.2'

.woodpecker/docker.yml

@@ -13,7 +13,7 @@ depends_on:
   - web
 
 variables:
-  - &golang_image 'docker.io/golang:1.21.3'
+  - &golang_image 'docker.io/golang:1.21.4'
   - &node_image 'docker.io/node:21-alpine'
   - &xgo_image 'docker.io/techknowlogick/xgo:go-1.21.4'
   - &xgo_version 'go-1.21.2'

.woodpecker/docs.yml

@@ -21,7 +21,7 @@ when:
     evaluate: 'TASK == "docs"'
 
 variables:
-  - &golang_image 'docker.io/golang:1.21.3'
+  - &golang_image 'docker.io/golang:1.21.4'
   - &node_image 'docker.io/node:21-alpine'
 
 steps:

.woodpecker/test.yml

@@ -9,7 +9,7 @@ when:
       - renovate/*
 
 variables:
-  - &golang_image 'docker.io/golang:1.21.3'
+  - &golang_image 'docker.io/golang:1.21.4'
   - &when
     - path: &when_path # related config files
         - '.woodpecker/test.yml'