Skip redundant validation checks in RecordBatch#project (#8583)

# Which issue does this PR close?

- Closes #8591.

# Rationale for this change

RecordBatch project currently uses the validating factory function.
Since project starts from a valid RecordBatch these checks are
redundant. A small amount of work can be saved by using `new_unchecked`
instead.

A change I'm working on for DataFusion uses `RecordBatch#project` in the
inner expression evaluation loop to reduce the amount of redundant array
filtering `case` expressions need to do. While a micro optimisation,
avoiding redundant work in inner loops seems worthwhile.

# What changes are included in this PR?

- Use `new_unchecked` instead of `try_new_with_options` in
`RecordBatch#project`

# Are these changes tested?

No additional tests added.
Performance difference proven via microbenchmark

# Are there any user-facing changes?

No

Co-authored-by: Andrew Lamb <andrew@nerdnetworks.org>

Author: pepijnve

arrow-array/src/record_batch.rs

@@ -445,14 +445,16 @@ impl RecordBatch {
             })
             .collect::<Result<Vec<_>, _>>()?;
 
-        RecordBatch::try_new_with_options(
-            SchemaRef::new(projected_schema),
-            batch_fields,
-            &RecordBatchOptions {
-                match_field_names: true,
-                row_count: Some(self.row_count),
-            },
-        )
+        unsafe {
+            // Since we're starting from a valid RecordBatch and project
+            // creates a strict subset of the original, there's no need to
+            // redo the validation checks in `try_new_with_options`.
+            Ok(RecordBatch::new_unchecked(
+                SchemaRef::new(projected_schema),
+                batch_fields,
+                self.row_count,
+            ))
+        }
     }
 
     /// Normalize a semi-structured [`RecordBatch`] into a flat table.