Run functest jobs on bookworm

We were running these test jobs on bullseye which is getting a bit old.
Additionally, it seems that the debootstrap on bullseye may not be able
to build jammy on arm64? Attempt to address that via executing on a
newer platform.

Change-Id: I54195c3f4500dcbcb92c5abb2a14f3078b2461dc

.zuul.d/jobs.yaml

@@ -18,7 +18,7 @@
     description: |
       This is the base set of stable tests
     parent: dib-functests-base
-    nodeset: debian-bullseye
+    nodeset: debian-bookworm
     vars:
       dib_functests:
         - containerfile/jammy-build-succeeds
@@ -42,7 +42,7 @@
     name: dib-functests-arm64-deb
     description: |
       ARM64 build tests (Debian-like distros)
-    nodeset: debian-bullseye-arm64
+    nodeset: debian-bookworm-arm64
     parent: dib-functests-base
     vars:
       dib_functests:
@@ -55,7 +55,7 @@
     name: dib-functests-arm64-rpm
     description: |
       ARM64 build tests (RPM-like distros)
-    nodeset: debian-bullseye-arm64
+    nodeset: debian-bookworm-arm64
     parent: dib-functests-base
     vars:
       dib_functests: