Avoid libpng compilation on Windows spamming the Microsoft banner

Author: ISSOtm

.github/workflows/create-release-artifacts.yml

@@ -39,7 +39,8 @@ jobs:
         shell: cmd
         run: |
           call .github\scripts\msvc-env.bat ${{ matrix.bits }}
-          cmake -S . -B build -G Ninja -DFETCHCONTENT_BASE_DIR="${{ env.DEPS_ROOT_DIR }}"
+          cmake -S . -B build -G Ninja ^
+                -DFETCHCONTENT_BASE_DIR="${{ env.DEPS_ROOT_DIR }}" -DCMAKE_C_FLAGS="/nologo"
           cmake --build build
       - name: Package binaries
         working-directory: build

.github/workflows/testing.yml

@@ -182,8 +182,8 @@ jobs:
         shell: cmd
         run: | # ASan seems to be broken on Windows, so we disable it.
           call .github\scripts\msvc-env.bat ${{ matrix.bits }}
-          cmake -S . -B build -G Ninja --preset develop -DSANITIZERS=OFF ^
-                -DTESTS_OS_NAME=${{ matrix.os }} -DFETCHCONTENT_BASE_DIR="${{ env.DEPS_ROOT_DIR }}"
+          cmake -S . -B build -G Ninja --preset develop -DSANITIZERS=OFF -DTESTS_OS_NAME=${{ matrix.os }} ^
+                -DFETCHCONTENT_BASE_DIR="${{ env.DEPS_ROOT_DIR }}" -DCMAKE_C_FLAGS="/nologo"
           cmake --build build
       - name: Package binaries
         working-directory: build