Inconsistent Column Name Quoting in DuckDB with PostgreSQL Integration

### What happens?

When using the DuckDB package in Python to import a CSV file into PostgreSQL, I've observed inconsistent behavior regarding column names:

- **Lower Case Column Titles**: if the CSV file's header (column titles) is in _lower case_, the corresponding column names in the created PostgreSQL table appear without quotes.

- **Upper Case Column Titles**: if the CSV file's header is in _upper case_, the corresponding column names in the PostgreSQL table are enclosed in quotes, even when the `preserve_identifier_case` setting is set to `False`.

This behavior appears inconsistent and may indicate a bug. Below is the Python script used for testing this issue.

### To Reproduce

```python

#!/usr/bin/env python
# coding: utf-8

import duckdb as db

con = db.connect()
con.install_extension("postgres")
con.load_extension("postgres")
con.execute("set preserve_identifier_case = false;")

sql_cmd = """
attach 'host=localhost
port=5432
dbname=db
user=jonhdoe
password=marydoe' as pg (type postgres);
"""
con.sql(sql_cmd)

sql_cmd = """
drop table if exists pg.list;
create table pg.list_lower as
select * from 'test_lower.csv';
"""
con.sql(sql_cmd)

sql_cmd = """
drop table if exists pg.list;
create table pg.list_upper as
select * from 'test_upper.csv';
"""
con.sql(sql_cmd)

con.close()
```

```csv
CUST_ID,START_DATE,END_DATE,TRANS_ID,DATE,YEAR,MONTH,DAY,EXP_TYPE,AMOUNT
CI6XLYUMQK,2015-05-01,,T8I9ZB5A6X90UG8,2015-09-11,2015,9,11,Motor/Travel,20.27
CI6XLYUMQK,2015-05-01,,TZ4JSLS7SC7FO9H,2017-02-08,2017,2,8,Motor/Travel,12.85
CI6XLYUMQK,2015-05-01,,TTUKRDDJ6B6F42H,2015-08-01,2015,8,1,Housing,383.8
CI6XLYUMQK,2015-05-01,,TDUHFRUKGPPI6HD,2019-03-16,2019,3,16,Entertainment,5.72
CI6XLYUMQK,2015-05-01,,T0JBZHBMSVRFMMD,2015-05-15,2015,5,15,Entertainment,11.06
CI6XLYUMQK,2015-05-01,,TZBO76X87ZUWBJ0,2016-02-22,2016,2,22,Motor/Travel,20.37
CI6XLYUMQK,2015-05-01,,T8YEYMHF208963N,2015-08-20,2015,8,20,Entertainment,15.97
CI6XLYUMQK,2015-05-01,,TQNUZKC8K4W0S9H,2016-07-16,2016,7,16,Entertainment,17.46
CI6XLYUMQK,2015-05-01,,TQJ3BTAB7E449ZN,2018-12-23,2018,12,23,Groceries,26.77
CI6XLYUMQK,2015-05-01,,TMFITCZBN0YK9FM,2020-12-02,2020,12,2,Entertainment,8.24
CI6XLYUMQK,2015-05-01,,TEDY6MR01ELTHWY,2018-02-25,2018,2,25,Groceries,9.27
CI6XLYUMQK,2015-05-01,,TRUQRD6ME4A13I0,2019-04-15,2019,4,15,Groceries,8.97
CI6XLYUMQK,2015-05-01,,T13LUKGW0O8SAIQ,2017-01-20,2017,1,20,Motor/Travel,23.95
CI6XLYUMQK,2015-05-01,,T8DBBZQXIR0X93O,2015-06-14,2015,6,14,Groceries,8.24
CI6XLYUMQK,2015-05-01,,T4H2B228GNWC4ES,2018-03-27,2018,3,27,Entertainment,9.58
CI6XLYUMQK,2015-05-01,,T0TGOW0T3504WJ3,2020-05-06,2020,5,6,Groceries,17.44
```

```csv
cust_id,start_date,end_date,trans_id,date,year,month,day,exp_type,amount
CI6XLYUMQK,2015-05-01,,T8I9ZB5A6X90UG8,2015-09-11,2015,9,11,Motor/Travel,20.27
CI6XLYUMQK,2015-05-01,,TZ4JSLS7SC7FO9H,2017-02-08,2017,2,8,Motor/Travel,12.85
CI6XLYUMQK,2015-05-01,,TTUKRDDJ6B6F42H,2015-08-01,2015,8,1,Housing,383.8
CI6XLYUMQK,2015-05-01,,TDUHFRUKGPPI6HD,2019-03-16,2019,3,16,Entertainment,5.72
CI6XLYUMQK,2015-05-01,,T0JBZHBMSVRFMMD,2015-05-15,2015,5,15,Entertainment,11.06
CI6XLYUMQK,2015-05-01,,TZBO76X87ZUWBJ0,2016-02-22,2016,2,22,Motor/Travel,20.37
CI6XLYUMQK,2015-05-01,,T8YEYMHF208963N,2015-08-20,2015,8,20,Entertainment,15.97
CI6XLYUMQK,2015-05-01,,TQNUZKC8K4W0S9H,2016-07-16,2016,7,16,Entertainment,17.46
CI6XLYUMQK,2015-05-01,,TQJ3BTAB7E449ZN,2018-12-23,2018,12,23,Groceries,26.77
CI6XLYUMQK,2015-05-01,,TMFITCZBN0YK9FM,2020-12-02,2020,12,2,Entertainment,8.24
CI6XLYUMQK,2015-05-01,,TEDY6MR01ELTHWY,2018-02-25,2018,2,25,Groceries,9.27
CI6XLYUMQK,2015-05-01,,TRUQRD6ME4A13I0,2019-04-15,2019,4,15,Groceries,8.97
CI6XLYUMQK,2015-05-01,,T13LUKGW0O8SAIQ,2017-01-20,2017,1,20,Motor/Travel,23.95
CI6XLYUMQK,2015-05-01,,T8DBBZQXIR0X93O,2015-06-14,2015,6,14,Groceries,8.24
CI6XLYUMQK,2015-05-01,,T4H2B228GNWC4ES,2018-03-27,2018,3,27,Entertainment,9.58
CI6XLYUMQK,2015-05-01,,T0TGOW0T3504WJ3,2020-05-06,2020,5,6,Groceries,17.44
```

### OS:

MacOS X sequoia 15.5 M2 aarch64

### DuckDB Version:

v1.2.2 7c039464e4

### DuckDB Client:

1.3.0

### Hardware:

M2

### Full Name:

Carlos Rogerio Camargo

### Affiliation:

Universidade Federal de Santa Catarina

### What is the latest build you tested with? If possible, we recommend testing with the latest nightly build.

I have tested with a stable release

### Did you include all relevant data sets for reproducing the issue?

Yes

### Did you include all code required to reproduce the issue?

- [x] Yes, I have

### Did you include all relevant configuration (e.g., CPU architecture, Python version, Linux distribution) to reproduce the issue?

- [x] Yes, I have