use main (v1.x) branch for spdlog until next release for libfmt11 fix

Author: lkeegan

.github/workflows/release.yml

@@ -6,7 +6,7 @@ env:
   SYMENGINE_VERSION: "master"
   GMP_VERSION: "6.3.0"
   MPFR_VERSION: "4.2.1"
-  SPDLOG_VERSION: "v1.15.0"
+  SPDLOG_VERSION: "v1.x"
   LIBTIFF_VERSION: "v4.7.0"
   FMT_VERSION: "11.1.1"
   TBB_VERSION: "v2022.0.0"