unable to encode -25518 into binary format for date (OID 1082)

**Describe the bug**
a bit of context, copy of a table from Adventureworks database , in one of the tables there is a date which is before 1970-1-1 (unix time) , so this delivers a minus number and there it crashes ? to write data to postgres table.

**To Reproduce**
Steps to reproduce the behavior:

If possible, please provide runnable example such as:

```package main

import (
"context"
"fmt"
"log"
"time"

"github.com/apache/arrow/go/v14/arrow"
"github.com/apache/arrow/go/v14/arrow/array"
"github.com/apache/arrow/go/v14/arrow/memory"
"github.com/jackc/pgx/v5"
)

func main() {
conn, err := pgx.Connect(context.Background(), "postgres://:?sslmode=disable")
if err != nil {
log.Fatalf("connect: %v", err)
}
defer conn.Close(context.Background())

// Voorbeeld datum vóór 1970
daysSinceEpoch := int32((time.Date(1960, 1, 1, 0, 0, 0, 0, time.UTC).Unix()) / 86400)

// Arrow array maken met 1 element: 1960-01-01
pool := memory.NewGoAllocator()
b := array.NewDate32Builder(pool)
b.Append(arrow.Date32(daysSinceEpoch))
arr := b.NewArray()
defer arr.Release()

rows := pgx.CopyFromRows([][]interface{}{
{arr.(*array.Date32).Value(0)},
})

_, err = conn.Exec(context.Background(), `DROP TABLE IF EXISTS bug`)
if err != nil {
log.Fatalf("drop table: %v", err)
}

_, err = conn.Exec(context.Background(), `CREATE TABLE bug (before1970 DATE)`)
if err != nil {
log.Fatalf("create table: %v", err)
}

// Invoegen met pgx.CopyFrom
_, err = conn.CopyFrom(context.Background(),
pgx.Identifier{"bug"},
[]string{"before1970"},
rows,
)
if err != nil {
log.Fatalf("copyfrom: %v", err)
}

fmt.Println("✅ Insert succeeded")
}

```
Please run your example with the race detector enabled. For example, `go run -race main.go` or `go test -race`.

**Expected behavior**
the row (field) should be inserted into the target tabel (bug(before1970))

**Actual behavior**
ERROR : unable to encode -25518 into binary format for date (OID 1082)

**Version**
- Go: `$ go version` -> [e.g. go version go1.18.3 darwin/amd64]
- PostgreSQL: PostgreSQL 17.5 on x86_64-pc-linux-musl, compiled by gcc (Alpine 14.2.0) 14.2.0, 64-bit
-
- pgx: `$ grep 'github.com/jackc/pgx/v[0-9]' go.mod` -> [e.g. v4.16.1]

module bug

go 1.24.2

require (
github.com/apache/arrow/go/arrow v0.0.0-20211112161151-bc219186db40
github.com/apache/arrow/go/v14 v14.0.2
github.com/jackc/pgx/v5 v5.7.5
)

require (
github.com/goccy/go-json v0.10.2 // indirect
github.com/google/flatbuffers v23.5.26+incompatible // indirect
github.com/jackc/pgpassfile v1.0.0 // indirect
github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
github.com/klauspost/cpuid/v2 v2.2.5 // indirect
github.com/zeebo/xxh3 v1.0.2 // indirect
golang.org/x/crypto v0.37.0 // indirect
golang.org/x/mod v0.17.0 // indirect
golang.org/x/sync v0.13.0 // indirect
golang.org/x/sys v0.32.0 // indirect
golang.org/x/text v0.24.0 // indirect
golang.org/x/tools v0.21.1-0.20240508182429-e35e4ccd0d2d // indirect
golang.org/x/xerrors v0.0.0-20220907171357-04be3eba64a2 // indirect
)

**Additional context**
Add any other context about the problem here.

Start with the provided Go reproducer, focusing on pgx.CopyFrom and date encoding for PostgreSQL OID 1082. Confirm the failure with the pre-1970 Arrow Date32 value, then verify that inserting it into the bug table succeeds without the binary-format encoding error.

Written by the indexing model from the issue text.