fix(tool): Use uppercase for custom CPU template files

I renamed the custom CPU template files uppercase, but I forgot to
update their names in release.sh.

Fixes: 2862941 ("chore: Use uppercase for custom CPU templates")
Signed-off-by: Takahiro Itazuri <itazur@amazon.com>

Author: zulinx86

tools/release.sh

@@ -177,7 +177,7 @@ cp -v -t "$RELEASE_DIR" LICENSE NOTICE THIRD-PARTY
 check_swagger_artifact src/firecracker/swagger/firecracker.yaml "$VERSION"
 cp -v src/firecracker/swagger/firecracker.yaml "$RELEASE_DIR/firecracker_spec-$VERSION.yaml"
 
-CPU_TEMPLATES=(c3 t2 t2s t2cl t2a v1n1)
+CPU_TEMPLATES=(C3 T2 T2S T2CL T2A V1N1)
 for template in "${CPU_TEMPLATES[@]}"; do
     cp -v tests/data/custom_cpu_templates/$template.json $RELEASE_DIR/$template-$VERSION.json
 done