ci: skip submodule update when no .gitmodules

.github/workflows/ci.yml

@@ -16,6 +16,10 @@ jobs:
       - name: Checkout submodules (retry)
         run: |
           set -euo pipefail
+          if [ ! -f .gitmodules ]; then
+            echo "No .gitmodules found; skipping submodule update."
+            exit 0
+          fi
           git submodule sync --recursive
           for attempt in 1 2 3 4 5; do
             if git -c protocol.version=2 submodule update --init --force --depth=1 --recursive; then
@@ -101,6 +105,10 @@ jobs:
       - name: Checkout submodules (retry)
         run: |
           set -euo pipefail
+          if [ ! -f .gitmodules ]; then
+            echo "No .gitmodules found; skipping submodule update."
+            exit 0
+          fi
           git submodule sync --recursive
           for attempt in 1 2 3 4 5; do
             if git -c protocol.version=2 submodule update --init --force --depth=1 --recursive; then
@@ -217,6 +225,10 @@ jobs:
       - name: Checkout submodules (retry)
         run: |
           set -euo pipefail
+          if [ ! -f .gitmodules ]; then
+            echo "No .gitmodules found; skipping submodule update."
+            exit 0
+          fi
           git submodule sync --recursive
           for attempt in 1 2 3 4 5; do
             if git -c protocol.version=2 submodule update --init --force --depth=1 --recursive; then
@@ -293,6 +305,10 @@ jobs:
       - name: Checkout submodules (retry)
         run: |
           set -euo pipefail
+          if [ ! -f .gitmodules ]; then
+            echo "No .gitmodules found; skipping submodule update."
+            exit 0
+          fi
           git submodule sync --recursive
           for attempt in 1 2 3 4 5; do
             if git -c protocol.version=2 submodule update --init --force --depth=1 --recursive; then
@@ -389,6 +405,10 @@ jobs:
       - name: Checkout submodules (retry)
         run: |
           set -euo pipefail
+          if [ ! -f .gitmodules ]; then
+            echo "No .gitmodules found; skipping submodule update."
+            exit 0
+          fi
           git submodule sync --recursive
           for attempt in 1 2 3 4 5; do
             if git -c protocol.version=2 submodule update --init --force --depth=1 --recursive; then