add python 3.6 to build

Author: joeljonsson

.github/workflows/main.yml

@@ -42,7 +42,7 @@ jobs:
       # Indicates the location of the vcpkg as a Git submodule of the project repository.
       VCPKG_ROOT: ${{ github.workspace }}/external/LibAPR/vcpkg
       CIBW_ENVIRONMENT_WINDOWS: EXTRA_CMAKE_ARGS="-DCMAKE_TOOLCHAIN_FILE=D:\\a\\PyLibAPR\\PyLibAPR\\external\\LibAPR\\vcpkg\\scripts\\buildsystems\\vcpkg.cmake -DVCPKG_MANIFEST_DIR=D:\\a\\PyLibAPR\\PyLibAPR\\external\\LibAPR\\"
-      CIBW_BUILD: "cp37-* cp38-* cp39-*"
+      CIBW_BUILD: "cp36-* cp37-* cp38-* cp39-*"
       CIBW_ARCHS: "auto64"
       CIBW_MANYLINUX_X86_64_IMAGE: "manylinux_2_24"
       CIBW_BUILD_VERBOSITY: 1
@@ -128,7 +128,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.7, 3.8, 3.9]
+        python-version: [3.6, 3.7, 3.8, 3.9]
         include:
           - os: windows-latest
             triplet: x64-windows