add suffix to fuzz test files

So that they can be excluded in ziglang/zig build by suffix.

src/deflate.zig

@@ -669,11 +669,11 @@ test "flate deflate file tokenization" {
             .tokens_count = .{ 235, 234, 234, 234, 234, 234 },
         },
         .{
-            .data = @embedFile("testdata/fuzz/roundtrip1"),
+            .data = @embedFile("testdata/fuzz/roundtrip1.input"),
             .tokens_count = .{ 333, 331, 331, 331, 331, 331 },
         },
         .{
-            .data = @embedFile("testdata/fuzz/roundtrip2"),
+            .data = @embedFile("testdata/fuzz/roundtrip2.input"),
             .tokens_count = .{ 334, 334, 334, 334, 334, 334 },
         },
     };

src/flate.zig

@@ -97,19 +97,19 @@ test "flate compress/decompress" {
             .store_size = 36967,
         },
         .{
-            .data = @embedFile("testdata/fuzz/roundtrip1"),
+            .data = @embedFile("testdata/fuzz/roundtrip1.input"),
             .gzip_sizes = [_]usize{ 373, 370, 370, 370, 370, 370 },
             .huffman_only_size = 393,
             .store_size = 393,
         },
         .{
-            .data = @embedFile("testdata/fuzz/roundtrip2"),
+            .data = @embedFile("testdata/fuzz/roundtrip2.input"),
             .gzip_sizes = [_]usize{ 373, 373, 373, 373, 373, 373 },
             .huffman_only_size = 394,
             .store_size = 394,
         },
         .{
-            .data = @embedFile("testdata/fuzz/deflate-stream-out"),
+            .data = @embedFile("testdata/fuzz/deflate-stream.expect"),
             .gzip_sizes = [_]usize{ 351, 347, 347, 347, 347, 347 },
             .huffman_only_size = 498,
             .store_size = 747,

src/inflate.zig

@@ -488,7 +488,7 @@ test "flate.Inflate fuzzing tests" {
         out: []const u8 = "",
         err: ?anyerror = null,
     }{
-        .{ .input = "deflate-stream", .out = @embedFile("testdata/fuzz/deflate-stream-out") }, // 0
+        .{ .input = "deflate-stream", .out = @embedFile("testdata/fuzz/deflate-stream.expect") }, // 0
         .{ .input = "empty-distance-alphabet01" },
         .{ .input = "empty-distance-alphabet02" },
         .{ .input = "end-of-stream", .err = error.EndOfStream },
@@ -531,7 +531,7 @@ test "flate.Inflate fuzzing tests" {
     };
 
     inline for (cases, 0..) |c, case_no| {
-        var in = std.io.fixedBufferStream(@embedFile("testdata/fuzz/" ++ c.input));
+        var in = std.io.fixedBufferStream(@embedFile("testdata/fuzz/" ++ c.input ++ ".input"));
         var out = std.ArrayList(u8).init(testing.allocator);
         defer out.deinit();
         errdefer std.debug.print("test case failed {}\n", .{case_no});