Fix a typo in CI build option (#4196)

Author: WeiqunZhang

.github/workflows/apps.yml

@@ -96,7 +96,7 @@ jobs:
             -DCMAKE_VERBOSE_MAKEFILE=ON           \
             -DCMAKE_CXX_COMPILER_LAUNCHER=ccache  \
             -DAMReX_FFT=ON                        \
-            -DAMReX_LINEAR_SOLVER_INCFLO=OFF
+            -DAMReX_LINEAR_SOLVERS_INCFLO=OFF
         cmake --build WarpX/build -j 4
 
         ccache -s