Enable one level of git submodules for soundness checks

Motivation:

Submodules are used by some repos.

Note:  Not all the soundness checks strictly need submodules
but when working locally you'll have submodules checked out
which can break the various linters so to keep local workflows
functional it's best to get submodules for PR too.

Modifications:

Make the checkout action get one level of submodules for
soundness checks.

Result:

Soundness more generally correct.

Author: PeterAdams-A

.github/workflows/soundness.yml

@@ -82,6 +82,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Mark the workspace as safe
         # https://github.com/actions/checkout/issues/766
         run: git config --global --add safe.directory ${GITHUB_WORKSPACE}
@@ -102,6 +103,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Run documentation check
         run: |
           apt-get -qq update && apt-get -qq -y install curl yq
@@ -117,6 +119,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Run unacceptable language check
         env:
           UNACCEPTABLE_WORD_LIST: ${{ inputs.unacceptable_language_check_word_list}}
@@ -132,6 +135,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Run license header check
         env:
           PROJECT_NAME: ${{ inputs.license_header_check_project_name }}
@@ -147,6 +151,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Run broken symlinks check
         run: curl -s https://raw.githubusercontent.com/swiftlang/github-workflows/refs/heads/main/.github/workflows/scripts/check-broken-symlinks.sh | bash
 
@@ -162,6 +167,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Mark the workspace as safe
         # https://github.com/actions/checkout/issues/766
         run: git config --global --add safe.directory ${GITHUB_WORKSPACE}
@@ -182,6 +188,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Mark the workspace as safe
         # https://github.com/actions/checkout/issues/766
         run: git config --global --add safe.directory ${GITHUB_WORKSPACE}
@@ -200,6 +207,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Run yamllint
         run: |
           which yamllint >/dev/null || ( apt-get update && apt-get install -y yamllint )
@@ -215,6 +223,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Run flake8
         run: |
           pip3 install flake8 flake8-import-order