Enable testing on Windows

It was previously disabled on Windows as it was believed that the gnat_arm_elf
toolchain would behave the same on both Windows and Linux. However, from a post
on the Ada forum, it seems that there may be cases where projects build on Linux
but not on Windows. Therefore, we re-enable our testsuite on Windows out of an
abundance of caution.

Author: damaki

.github/workflows/main.yaml

@@ -43,28 +43,18 @@ jobs:
             echo "::endgroup::"
           done
 
-      # Don't run tests on Windows since it's so slow compared to Linux.
-      #
-      # Once we've proven that the runtimes can be built on Windows (in the
-      # above step), there's not much point in also building test apps against
-      # the runtimes since the Windows and Linux gnat_arm_elf toolchains should
-      # behave the same at this point, and we're not interested in checking
-      # for differences in those toolchains here.
-
       - name: Install Test Dependencies
-        if: ${{ matrix.os != 'windows-latest' }}
         run: |
           pip install -r tests/requirements.txt
 
       - name: Run tests
-        if: ${{ matrix.os != 'windows-latest' }}
         run: |
           cd tests
           pytest . -v --junit-xml=reports/runtime-tests.xml
 
       - name: Test Report
         uses: dorny/test-reporter@v2.6.0
-        if: ${{ !cancelled() && (matrix.os != 'windows-latest') }} # run this step even if previous step failed
+        if: ${{ !cancelled() }} # run this step even if previous step failed
         with:
           name: Runtime Tests
           path: tests/reports/*.xml