matrix: add 32bit and arm64, remove bionic

Somehow bionic crept back in, and we don't have 32-bit or arm64 targets,
so adding those to sched here.

src/test/generate-matrix.py

@@ -30,12 +30,14 @@ def __init__(self):
             if match:
                 self.tag = match.group(1)
 
-    def create_docker_tag(self, image, env, command):
+    def create_docker_tag(self, image, env, command, platform):
         """Create docker tag string if this is master branch or a tag"""
         if self.branch == "master" or self.tag:
             tag = f"{DOCKER_REPO}:{image}"
             if self.tag:
                 tag += f"-{self.tag}"
+            if platform is not None:
+                tag += "-" + platform.split("/")[1]
             env["DOCKER_TAG"] = tag
             command += f" --tag={tag}"
             return True, command
@@ -52,13 +54,19 @@ def add_build(
         docker_tag=False,
         coverage=False,
         recheck=True,
+        platform=None,
         command_args="",
     ):
         """Add a build to the matrix.include array"""
 
         # Extra environment to add to this command:
         env = env or {}
 
+        needs_buildx = False
+        if platform:
+            command_args += f"--platform={platform}"
+            needs_buildx = True
+
         # The command to run:
         command = f"{docker_run_checks} -j{jobs} --image={image} {command_args}"
 
@@ -68,7 +76,7 @@ def add_build(
 
         if docker_tag:
             #  Only export docker_tag if this is main branch or a tag:
-            docker_tag, command = self.create_docker_tag(image, env, command)
+            docker_tag, command = self.create_docker_tag(image, env, command, platform)
 
         if coverage:
             env["COVERAGE"] = "t"
@@ -94,6 +102,7 @@ def add_build(
                 "branch": self.branch,
                 "coverage": coverage,
                 "docker_tag": docker_tag,
+                "needs_buildx": needs_buildx,
                 "create_release": create_release,
             }
         )
@@ -107,6 +116,27 @@ def __str__(self):
 
 matrix = BuildMatrix()
 
+# Debian: no args
+matrix.add_build(name="bookworm")
+
+# Debian: 32b
+matrix.add_build(
+    name="bookworm - 32 bit",
+    image="bookworm",
+    platform="linux/386",
+    docker_tag=True,
+)
+
+# Debian: arm64, expensive, only on master and tags, only install
+if matrix.branch == 'master' or matrix.tag:
+    matrix.add_build(
+        name="bookworm - arm64",
+        image="bookworm",
+        platform="linux/arm64",
+        docker_tag=True,
+        command_args="--install-only ",
+    )
+
 # Debian: gcc-12, distcheck
 matrix.add_build(
     name="bookworm - gcc-12,distcheck",
@@ -149,13 +179,6 @@ def __str__(self):
     docker_tag=True,
 )
 
-# Ubuntu 18.04: py3.8
-matrix.add_build(
-    name="bionic",
-    image="bionic",
-    docker_tag=True,
-)
-
 # Ubuntu 20.04: py3.8
 matrix.add_build(
     name="focal",