.github: ensure clean and recursive submodules

Minor change, mostly for consistency across repos.

[skip ci]

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

.github/workflows/build.yml

@@ -17,7 +17,8 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          submodules: 'true'
+          clean: true
+          submodules: recursive
 
       - name: Set Build Variables
         id: vars

.github/workflows/regression.yml

@@ -21,7 +21,8 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          submodules: 'true'
+          clean: true
+          submodules: recursive
 
       - name: Clean up cruft ...
         run: |

.github/workflows/release.yml

@@ -29,7 +29,8 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
-          submodules: 'true'
+          clean: true
+          submodules: recursive
 
       - name: Set Release Variables
         id: vars