fix(ci): don't recurse submodules when bumping the engine pointer

TechEngine carries TechAPI back as a submodule, so `git submodule
update --recursive` follows that cycle — TechEngine/TechAPI/TechEngine/
TechAPI/… — re-fetching the million-file data tree at every level until
the runner dies with "No space left on device":

    fatal: Unable to checkout '679e487…' in submodule path
    'TechEngine/TechAPI/TechEngine/TechAPI/TechEngine/TechAPI/…'

Every bump-engine run has failed this way since 2026-08-03, which is
when the job started switching branches before touching the submodule
and so began re-resolving it from scratch. The submodule pointer has
not moved automatically since.

The gitlink being bumped is at this repo's top level; nothing below it
needs updating, so drop --recursive from both submodule commands.

Refs #1

Author: Seungpyo1007

.github/workflows/bump-engine.yml

@@ -38,8 +38,13 @@ jobs:
           # committed to.
           git fetch origin develop
           git checkout -B develop origin/develop
-          git submodule update --init --recursive TechEngine
-          git submodule update --remote --recursive TechEngine
+          # NOT --recursive. TechEngine carries TechAPI back as a submodule, so
+          # recursing follows that cycle — TechEngine/TechAPI/TechEngine/… — and
+          # each level re-fetches the million-file data tree until the runner
+          # reports "No space left on device". The gitlink being bumped is at
+          # this repo's top level; there is nothing below it to update.
+          git submodule update --init TechEngine
+          git submodule update --remote TechEngine
           if git diff --quiet -- TechEngine; then
             echo "changed=false" >> "$GITHUB_OUTPUT"
             echo "Submodule already up to date — nothing to do."