build-unit-test-docker: cppcheck: update to latest release

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I96b42465931c6aef7bc4b4309c9746a002c508e8
diff --git a/scripts/build-unit-test-docker b/scripts/build-unit-test-docker
index 8d27481..b043cfa 100755
--- a/scripts/build-unit-test-docker
+++ b/scripts/build-unit-test-docker
@@ -104,7 +104,7 @@
         build_steps=[f"cp -a include/cereal/ {prefix}/include/"],
     ),
     "danmar/cppcheck": PackageDef(
-        rev="2.9",
+        rev="2.12.1",
         build_type="cmake",
     ),
     "CLIUtils/CLI11": PackageDef(