templates: linting: fix "error return value is not checked (errchkjson)

The linter is correct; given that these functions do not allow for an error
to be returned, we panic. Alternatively, we could return the error string
as output, or add a `//nolint:errchkjson` comment.

    templates/templates.go:17:3: Error return value of `(*encoding/json.Encoder).Encode` is not checked: unsafe type `interface{}` found (errchkjson)
            enc.Encode(v)
            ^

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

.golangci.yml

@@ -5,6 +5,7 @@ linters:
     - dogsled
     - dupword       # Detects duplicate words.
     - durationcheck
+    - errchkjson
     - exportloopref # Detects pointers to enclosing loop variables.
     - gocritic      # Metalinter; detects bugs, performance, and styling issues.
     - gocyclo

templates/templates.go

@@ -14,7 +14,11 @@ var basicFunctions = template.FuncMap{
 		buf := &bytes.Buffer{}
 		enc := json.NewEncoder(buf)
 		enc.SetEscapeHTML(false)
-		enc.Encode(v)
+		err := enc.Encode(v)
+		if err != nil {
+			panic(err)
+		}
+
 		// Remove the trailing new line added by the encoder
 		return strings.TrimSpace(buf.String())
 	},