GH-39208: [C++][Parquet] Remove deprecated AppendRowGroup(int64_t num…

…_rows) (#39209)

### Rationale for this change

Described in issue

### What changes are included in this PR?

Remove the function below:

```
    /// \note Deprecated since 1.3.0
    RowGroupWriter* AppendRowGroup(int64_t num_rows);
```

### Are these changes tested?

no

### Are there any user-facing changes?

no

* Closes: #39208

Authored-by: mwish <maplewish117@gmail.com>
Signed-off-by: Antoine Pitrou <antoine@python.org>

cpp/src/parquet/file_writer.cc

@@ -642,10 +642,6 @@ RowGroupWriter* ParquetFileWriter::AppendBufferedRowGroup() {
   return contents_->AppendBufferedRowGroup();
 }
 
-RowGroupWriter* ParquetFileWriter::AppendRowGroup(int64_t num_rows) {
-  return AppendRowGroup();
-}
-
 void ParquetFileWriter::AddKeyValueMetadata(
     const std::shared_ptr<const KeyValueMetadata>& key_value_metadata) {
   if (contents_) {

cpp/src/parquet/file_writer.h

@@ -147,9 +147,6 @@ class PARQUET_EXPORT ParquetFileWriter {
     // Perform any cleanup associated with the file contents
     virtual void Close() = 0;
 
-    /// \note Deprecated since 1.3.0
-    RowGroupWriter* AppendRowGroup(int64_t num_rows);
-
     virtual RowGroupWriter* AppendRowGroup() = 0;
     virtual RowGroupWriter* AppendBufferedRowGroup() = 0;
 
@@ -190,15 +187,6 @@ class PARQUET_EXPORT ParquetFileWriter {
   void Open(std::unique_ptr<Contents> contents);
   void Close();
 
-  // Construct a RowGroupWriter for the indicated number of rows.
-  //
-  // Ownership is solely within the ParquetFileWriter. The RowGroupWriter is only valid
-  // until the next call to AppendRowGroup or AppendBufferedRowGroup or Close.
-  // @param num_rows The number of rows that are stored in the new RowGroup
-  //
-  // \deprecated Since 1.3.0
-  RowGroupWriter* AppendRowGroup(int64_t num_rows);
-
   /// Construct a RowGroupWriter with an arbitrary number of rows.
   ///
   /// Ownership is solely within the ParquetFileWriter. The RowGroupWriter is only valid