Use a yes/no for the suppress_zeroes bool in the format

Roll this into the prior version bump for the dimension arrow
directions.

pcbnew/pcb_io/kicad_sexpr/pcb_io_kicad_sexpr.cpp

@@ -944,8 +944,11 @@ void PCB_IO_KICAD_SEXPR::format( const PCB_DIMENSION_BASE* aDimension, int aNest
                           m_out->Quotew( aDimension->GetOverrideText() ).c_str() );
         }
 
-        if( aDimension->GetSuppressZeroes() )
-            m_out->Print( 0, " suppress_zeroes" );
+
+        if( bool suppressZeroes = aDimension->GetSuppressZeroes() )
+        {
+            KICAD_FORMAT::FormatBool( m_out, 0, "suppress_zeroes", suppressZeroes );
+        }
 
         m_out->Print( 0, ")\n" );
     }

pcbnew/pcb_io/kicad_sexpr/pcb_io_kicad_sexpr.h

@@ -169,7 +169,7 @@ class PCB_IO_KICAD_SEXPR;   // forward decl
 //#define SEXPR_BOARD_FILE_VERSION    20241007  // Tracks can have soldermask layer and margin
 //#define SEXPR_BOARD_FILE_VERSION    20241009  // Evolve placement rule areas file format
 //#define SEXPR_BOARD_FILE_VERSION    20241010  // Graphic shapes can have soldermask layer and margin
-#define SEXPR_BOARD_FILE_VERSION      20241030  // Dimension arrow directions
+#define SEXPR_BOARD_FILE_VERSION      20241030  // Dimension arrow directions, suppress_zeroes normalization
 
 #define BOARD_FILE_HOST_VERSION       20200825  ///< Earlier files than this include the host tag
 #define LEGACY_ARC_FORMATTING         20210925  ///< These were the last to use old arc formatting

pcbnew/pcb_io/kicad_sexpr/pcb_io_kicad_sexpr_parser.cpp

@@ -4085,10 +4085,11 @@ PCB_DIMENSION_BASE* PCB_IO_KICAD_SEXPR_PARSER::parseDIMENSION( BOARD_ITEM* aPare
                     break;
 
                 case T_suppress_zeroes:
-                    dim->SetSuppressZeroes( true );
+                    dim->SetSuppressZeroes( parseMaybeAbsentBool( true ) );
                     break;
 
                 default:
+                    std::cerr << "Unknown format token: " << GetTokenString( token ) << std::endl;
                     Expecting( "prefix, suffix, units, units_format, precision, override_value, "
                                "suppress_zeroes" );
                 }