Upgrade Go to 1.24.3 (#31220)

* Upgrade Go to 1.24.3

Updates the following files:
- server/.go-version: 1.23.9 → 1.24.3
- server/build/Dockerfile.buildenv: golang:1.23.9-bullseye → golang:1.24.3-bullseye
- server/go.mod: go 1.23.0 → go 1.24.3, toolchain go1.23.9 → go1.24.3
- server/public/go.mod: go 1.23.0 → go 1.24.3, toolchain go1.23.9 → go1.24.3

Also fixes non-constant format string errors introduced by Go 1.24.3's stricter format string checking:
- Added response() helper function in slashcommands/util.go for simple string responses
- Removed unused responsef() function from slashcommands/util.go
- Replaced responsef() with response() for translated strings that don't need formatting
- Fixed fmt.Errorf and fmt.Fprintf calls to use proper format verbs instead of string concatenation
- Updated marketplace buildURL to handle format strings conditionally

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Update generated mocks for Go 1.24.3

Regenerated mocks using mockery v2.53.4 to ensure compatibility with Go 1.24.3.
This addresses mock generation failures that occurred with the Go upgrade.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Update to bookworm and fix non-existent sha

Signed-off-by: Stavros Foteinopoulos <stafot@gmail.com>

* fix non-constant format string

---------

Signed-off-by: Stavros Foteinopoulos <stafot@gmail.com>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Stavros Foteinopoulos <stafot@gmail.com>

server/platform/services/marketplace/client.go

@@ -119,7 +119,10 @@ func closeBody(r *http.Response) {
 }
 
 func (c *Client) buildURL(urlPath string, args ...any) string {
-	return fmt.Sprintf("%s/%s", strings.TrimRight(c.address, "/"), strings.TrimLeft(fmt.Sprintf(urlPath, args...), "/"))
+	if len(args) > 0 {
+		urlPath = fmt.Sprintf(urlPath, args...)
+	}
+	return fmt.Sprintf("%s/%s", strings.TrimRight(c.address, "/"), strings.TrimLeft(urlPath, "/"))
 }
 
 func (c *Client) doGet(u string) (*http.Response, error) {