ci: fix pypy conditional

The operator = doesn't do pattern matching in [[ ... ]] - operator ==
must be used instead.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>

.github/workflows/run_tests.yml

@@ -123,7 +123,7 @@ jobs:
         PYTHON_SYS_PREFIX="$(python -c 'import sys;print(sys.prefix)')"
         echo "PKG_CONFIG_PATH=${PYTHON_SYS_PREFIX}/lib/pkgconfig" >> $GITHUB_ENV
 
-        if [[ "${{ matrix.python-ruby-version.python }}" = pypy* ]] ; then
+        if [[ "${{ matrix.python-ruby-version.python }}" == pypy* ]] ; then
             # PyPy does not provide a config file for pkg-config
             # libpypy-c.so is provided in bin/libpypy-c.so for PyPy and bin/libpypy3-c.so for PyPy3
             echo "PYINC=-I${PYTHON_SYS_PREFIX}/include" >> $GITHUB_ENV