Revert "Run big-endian tests in CI"

This reverts commit 9406ff0.

Author: overlookmotel

.github/workflows/ci.yml

@@ -97,7 +97,7 @@ jobs:
 
   test-big-endian:
     name: Test big-endian # s390x-unknown-linux-gnu is a big-endian
-    # if: ${{ github.ref_name == 'main' }}
+    if: ${{ github.ref_name == 'main' }}
     runs-on: ubuntu-latest
     steps:
       - uses: taiki-e/checkout-action@b13d20b7cda4e2f325ef19895128f7ff735c0b3d # v1.3.1