zig 0.12.0: add stub for awslambda (see note)

The new version of awslambda will utilize the lambda_zig project in place. It will strictly
be glue between universal lambda and aws lambda handler definitions much the same way
as flexilib

src/awslambda.zig

@@ -0,0 +1,6 @@
+const std = @import("std");
+const lambda_zig = @import("lambda-zig");
+
+pub fn run() !void {
+    lambda_zig.run();
+}

src/universal_lambda.zig

@@ -7,7 +7,7 @@ const log = std.log.scoped(.universal_lambda);
 
 const runFn = blk: {
     switch (build_options.build_type) {
-        .awslambda => break :blk @import("lambda.zig").run,
+        .awslambda => break :blk @import("awslambda.zig").run,
         .standalone_server => break :blk runStandaloneServerParent,
         // In the case of flexilib, our root module is actually flexilib.zig
         // so we need to import that, otherwise we risk the dreaded "file exists