ci: Switch from "RelWithDebInfo" to "Release" config for MSVC jobs

It is reasonable to test a configuration that is used in the Bitcoin
Core build.

For MSVC, the "Release" config (/O2 /Ob2) is preferable over
"RelWithDebInfo" (/Zi /O2 /Ob1) for the following reasons:

1. /Ob2 can be slightly better than /Ob1 for performance;
see: https://learn.microsoft.com/en-us/cpp/build/reference/ob-inline-function-expansion

2. /Zi, which produces a separate PDB file that contains all the
symbolic debugging information, is incompatible with ccache; see:
https://learn.microsoft.com/en-us/cpp/build/reference/z7-zi-zi-debug-information-format
https://github.com/ccache/ccache/wiki/MS-Visual-Studio

.github/workflows/ci.yml

@@ -735,7 +735,7 @@ jobs:
         run: cmake -E env CFLAGS="/WX ${{ matrix.configuration.cpp_flags }}" cmake -B build -DSECP256K1_ENABLE_MODULE_RECOVERY=ON -DSECP256K1_BUILD_EXAMPLES=ON ${{ matrix.configuration.cmake_options }}
 
       - name: Build
-        run: cmake --build build --config RelWithDebInfo -- /p:UseMultiToolTask=true /maxCpuCount
+        run: cmake --build build --config Release -- /p:UseMultiToolTask=true /maxCpuCount
 
       - name: Binaries info
         # Use the bash shell included with Git for Windows.