Update CI for zig 0.14.1 and remove submodule step

.drone.yml

@@ -3,21 +3,14 @@ type: docker
 name: continuous integration
 
 environment:
-  ZIG_VERSION: 0.13.0
+  ZIG_VERSION: 0.14.1
 
 steps:
-  - name: submodules
-    image: ubuntu:latest
-    commands:
-      - apt-get update
-      - apt-get install -y git git-lfs
-      - git submodule update --init --recursive
-
   - name: build & test
     image: ubuntu:latest
     commands:
       - apt-get update
-      - apt-get install -y openssl xz-utils wget libsdl2-dev glslang-tools spirv-tools
+      - apt-get install -y git git-lfs openssl xz-utils wget libsdl2-dev glslang-tools spirv-tools
       - wget https://ziglang.org/download/$${ZIG_VERSION}/zig-linux-x86_64-$${ZIG_VERSION}.tar.xz
       - tar -xf zig-linux-x86_64-$${ZIG_VERSION}.tar.xz
       - export PATH=$PATH:$(pwd)/zig-linux-x86_64-$${ZIG_VERSION}