feat: error instead of panic on too many buffers

Currently this panics in `write_flatbuffer`. Panics print a double stack trace and are a bit weird
when they happen in a future.

Signed-off-by: Daniel King <[email protected]>

Author: danking

vortex-array/src/serde.rs

@@ -155,6 +155,13 @@ impl<'a> ArrayNodeFlatBuffer<'a> {
                 );
             }
         }
+        let n_buffers_recursive = array.nbuffers_recursive();
+        if u16::try_from(n_buffers_recursive).is_err() {
+            vortex_bail!(
+                "Array and all descendent arrays can have at most u16::MAX buffers: {}",
+                n_buffers_recursive
+            );
+        };
         Ok(Self {
             ctx,
             array,