ci: recursive checkouts and remove unused flaky workflow

Author: dignifiedquire

.github/workflows/ci.yaml

@@ -83,6 +83,8 @@ jobs:
     steps:
     - name: Checkout
       uses: actions/checkout@v4
+      with:
+        submodules: recursive
 
     - name: Set up Rust
       uses: dtolnay/rust-toolchain@stable

.github/workflows/flaky.yaml

@@ -55,6 +55,7 @@ jobs:
     - name: Checkout
       uses: actions/checkout@v4
       with:
+        submodules: recursive
         ref: ${{ inputs.git-ref }}
 
     - name: Install ${{ matrix.rust }} rust
@@ -158,6 +159,7 @@ jobs:
     - name: Checkout
       uses: actions/checkout@v4
       with:
+        submodules: recursive
         ref: ${{ inputs.git-ref }}
 
     - name: Install ${{ matrix.rust }}