Address deprecated warning in function check_grd

[barrettk]

Warning is self explanatory

> check_grd(.mod) 
# A tibble: 8 × 8
  ITERATION `GRD(1)`  `GRD(2)` `GRD(3)`  `GRD(4)`  `GRD(5)`   `GRD(6)`    `GRD(7)`
      <dbl>    <dbl>     <dbl>    <dbl>     <dbl>     <dbl>      <dbl>       <dbl>
1         5   50.4   -245.     -296.    -138.      -749.    -123.      -1066.     
2        10  206.     116.     -220.     397.     -3204.     -23.0      -136.     
3        15 -120.      25.0      62.0     54.0     -273.      39.7         5.78   
4        20   18.8     17.4     -22.6     18.5      -51.2     15.7       -10.0    
5        25   34.2     12.7     -21.0     68.6      149.      -6.22       15.0    
6        30    1.33    -1.54      0.504    2.91      37.8      1.83        0.969  
7        35    0.512    8.89     88.6      1.45       7.94    -0.00192     0.00827
8        37    0.136   -0.0489   -0.810   -0.0398    -0.115   -0.00192     0.00827
Warning message:
`check_nonmem_table_output()` was deprecated in bbr 1.5.0.
ℹ Please use `nm_file()` instead.
ℹ All functions calling `check_nonmem_table_output()` are being replaced from `nm_*()` functions. See ?nm_file for details.
ℹ The deprecated feature was likely used in the bbr package.
  Please report the issue at <https://github.com/metrumresearchgroup/bbr/issues>.
This warning is displayed once every 8 hours.
Call `lifecycle::last_lifecycle_warnings()` to see where this warning was generated.