Fix macOS build error

Author: exactly-one-kas

.github/workflows/build.yml

@@ -243,6 +243,11 @@ jobs:
         if: matrix.env.ninja_platform == 'mac'
         run: |
           cd dep/openssl/openssl
+
+          # this is necessary until https://github.com/openssl/openssl/issues/18720
+          # is fixed in OpenSSL 1.1.1r
+          export CFLAGS=-Wno-error=implicit-function-declaration
+
           ./Configure ${{ matrix.env.openssl_arch }} no-shared
           make