[bazel] Replace bazel sync with bazel fetch

For whatever reason they've changed `sync` to `fetch` with Bzlmod and
`sync` fully crashes Bazel when hybrid mode is disabled rather than
giving an error.

Signed-off-by: James Wainwright <james.wainwright@lowrisc.org>

rules/bitstreams.bzl

@@ -69,7 +69,7 @@ def _bitstreams_repo_impl(rctx):
     if result.return_code != 0:
         fail("Bitstream cache not initialized properly.")
 
-# The bitstream repo should be evaluated with `bazel sync --configure` after
+# The bitstream repo should be evaluated with `bazel fetch --configure` after
 # every Git checkout. Once the cache is initialized, a typical invocation will
 # find the latest cached artifacts and map them to Bazel targets.
 #
@@ -123,7 +123,7 @@ bitstreams_repo = repository_rule(
     # This rule depends on the Git repository, but there's no ergonomic way to
     # encode the dependency in Bazel. Instead, indicate that the rule depends on
     # something outside of Bazel's dependency graph and rely on the user calling
-    # `bazel sync --configure` when checking out new revisions. For historical
+    # `bazel fetch --configure` when checking out new revisions. For historical
     # context, see <https://github.com/lowRISC/opentitan/issues/16832>.
     configure = True,
 )

util/prep-bazel-airgapped-build.sh

@@ -115,14 +115,13 @@ if [[ ${AIRGAPPED_DIR_CONTENTS} == "ALL" || \
     --output bazel
   chmod +x bazel
 
-  # Make Bazel sync its own dependencies to the repository cache:
+  # Make Bazel fetch its own dependencies to the repository cache:
   # https://bazel.build/run/build#repository_cache_with_bazel_7_or_later
   mkdir -p "${BAZEL_AIRGAPPED_DIR}/empty_workspace"
   pushd "${BAZEL_AIRGAPPED_DIR}/empty_workspace"
     touch MODULE.bazel
-    touch WORKSPACE
     cp "${REPO_TOP}/.bazelversion" .
-    bazel sync --repository_cache="${BAZEL_AIRGAPPED_DIR}/${BAZEL_CACHEDIR}"
+    bazel fetch --repository_cache="${BAZEL_AIRGAPPED_DIR}/${BAZEL_CACHEDIR}"
   popd
   rm -rf "${BAZEL_AIRGAPPED_DIR}/empty_workspace"
 fi