add libarchive to the dependencies.

library for handling archives, like gzip, xz, zstd, et cetera.
This'll be crucial later on.

.github/workflows/ci.yaml

@@ -11,7 +11,7 @@ on:
 env:
   VCPKG_DISABLE_METRICS: 1
   VCPKG_ROOT: ${{github.workspace}}/.vcpkg
-  DEPS_VCPKG: glfw3:x64-linux-dynamic glfw3:x64-mingw-static
+  DEPS_VCPKG: glfw3:x64-linux-dynamic glfw3:x64-mingw-static libarchive:x64-linux-dynamic libarchive:x64-mingw-static
   WINEPREFIX: /tmp/wineprefix
 jobs:
   #
@@ -40,7 +40,13 @@ jobs:
       # setup vcpkg if the cache didn't hit
       - if: steps.vcpkg-cache.outputs.cache-hit != 'true'
         run: |
+          if [ -d "$VCPKG_ROOT" ]; then
+              cd "$VCPKG_ROOT"
+              git pull -f
+              cd -
+          else
               git clone https://github.com/microsoft/vcpkg.git "$VCPKG_ROOT"
+          fi
           "$VCPKG_ROOT/bootstrap-vcpkg.sh"
           "$VCPKG_ROOT/vcpkg" install $DEPS_VCPKG
       - name: compilation (using bulk compilation)

makefile

@@ -63,8 +63,8 @@ $(error neither VCPKG_ROOT nor pkg-config were available!)
 endif
 
 # use pkg-config to set the include and linker information
-CFLAGS  += $(shell pkg-config --cflags glfw3)
-LDFLAGS += $(shell pkg-config --libs   glfw3)
+CFLAGS  += $(shell pkg-config --cflags glfw3 libarchive)
+LDFLAGS += $(shell pkg-config --libs   glfw3 libarchive)
 
 # windows specific handling
 ifeq ($(ISWIN),1)