`load_rosters` and `load_rosters_weekly` are returning as character instead of integers

[tanho63]

Season and week of load_rosters columns are returning as character at the moment. These should be ints.

R> nflreadr::load_rosters(TRUE) |> tibble::tibble()
# A tibble: 123,226 × 30
   season team  position depth_chart_position jersey_number status full_name    first_name
   <chr>  <chr> <chr>    <chr>                <chr>         <chr>  <chr>        <chr>     
 1 1920   AKR   DL       E                    0             ACT    Scotty Bier… Bruce     
 2 1920   AKR   DL       E                    0             ACT    Budge Garre… Alfred    
 3 1920   AKR   DL       E                    0             ACT    George John… George    
 4 1920   AKR   DL       DG                   0             ACT    Al Nesser    Alfred    
 5 1920   AKR   DL       DG                   0             ACT    Tommy Tomlin John      
 6 1920   AKR   OL       C                    0             ACT    Russ Bailey  Russell   
 7 1920   AKR   OL       G                    0             ACT    George Brown George    
 8 1920   AKR   OL       G                    0             ACT    Alf Cobb     Alfred    
 9 1920   AKR   OL       OT                   0             ACT    Pike Johnson Karl      
10 1920   AKR   OL       G                    0             ACT    Frank Moran  Frank     
# … with 123,216 more rows, and 22 more variables: last_name <chr>, birth_date <date>,
#   height <chr>, weight <chr>, college <chr>, gsis_id <chr>, espn_id <chr>,
#   sportradar_id <chr>, yahoo_id <chr>, rotowire_id <chr>, pff_id <chr>, pfr_id <chr>,
#   fantasy_data_id <chr>, sleeper_id <chr>, years_exp <int>, headshot_url <chr>,
#   ngs_position <chr>, esb_id <chr>, gsis_it_id <chr>, smart_id <chr>, entry_year <chr>,
#   rookie_year <chr>

This causes problems on joins like in ffverse/ffscrapr#364 and ffverse/ffscrapr#365