read_excel with openpyxl engine doesn't close file after reading
```python
import pandas as pd

data = pd.read_excel('excel_file.xlsx', engine='openpyxl')
```
#### Problem description:
After running the above code in console, I switch to Excel and try to save 'excel_file.xlsx'. Excel raises an access error.

I tried to figure out if the file remains open using file descriptor. As output shows, it does:
```python
import os

import pandas as pd

xl_file_stat = os.stat(os.path.relpath('excel_file.xlsx'))

try:
    os.fstat(3)
except OSError:
    print('File is not open')

print('Reading excel file...')
data = pd.read_excel('excel_file.xlsx', engine='openpyxl')
print('File has been read')

if os.fstat(3) == xl_file_stat:
    print('File is open')
```

##### Output:
```
File is not open
Reading excel file...
File has been read
File is open
```

The problem may arise from the openpyxl's class `ExcelReader`. Its' `read()` method closes the archive if read-only attribute is set to False (openpyxl/reader/excel.py, rows 281-282):
```
        if not self.read_only:
            self.archive.close()
```

I'm not sure if it's a normal behavior of `ExcelReader`, but I expect `pd.read_excel()` to close the file in this case.

<details>
pandas: 0.25.3<br>
openpyxl: 3.0.0
</details>