Use alpine:3.21.0 as more recent Alpine versions are currently broken when compiling armv6 (serious compiler errors happening in random places)

DL6ER · DL6ER · commit 14fa1cc7e188 · 2025-01-24T19:09:55.000+01:00
Signed-off-by: DL6ER &lt;dl6er@dl6er.de&gt;
diff --git a/ftl-build/Dockerfile b/ftl-build/Dockerfile
@@ -1,4 +1,4 @@
-ARG CONTAINER="alpine:3.21"
+ARG CONTAINER="alpine:3.21.0"
 FROM ${CONTAINER} AS builder
 
 ARG TARGETPLATFORM
