[wpimath] Suppress the -Wmaybe-uninitialized warning in Eigen (#3378)

GCC 11 emits a false positive when compiling Eigen and breaks the
build.

Fixes #3363.

wpimath/src/main/native/eigeninclude/Eigen/src/Core/util/DisableStupidWarnings.h

@@ -61,6 +61,10 @@
     // See: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89325
     #pragma GCC diagnostic ignored "-Wattributes"
   #endif
+  #if __GNUC__==11
+    // This warning is a false positive
+    #pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
+  #endif
 #endif
 
 #if defined __NVCC__