[CI] skip import test on CentOS 7

Author: XuehaiPan

pyproject.toml

@@ -229,3 +229,10 @@ repair-wheel-command = [
     "delocate-wheel --verbose --ignore-missing-dependencies --no-sanitize-rpaths --require-archs {delocate_archs} -w {dest_dir} -v {wheel}",
     "pipx run abi3audit --verbose --strict {wheel}",
 ]
+
+[[tool.cibuildwheel.overrides]]
+select = "*linux*x86_64*"
+# CentOS 7 is too old to run import test. Do wheel installation test only.
+test-command = [
+    "echo 'Wheel is installed successfully'",
+]