Updated Alpine base image in Dockerfile

Author: rkoehn

Dockerfile

@@ -18,7 +18,7 @@
 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 # IN THE SOFTWARE.
 
-FROM python:3.11-alpine3.19 AS build
+FROM python:3.11-alpine3.21 AS build
 
 # Build-time flags
 ARG WITH_PLUGINS=true