use normalizePath() in find_package()

[AshesITR]

fixes #1759

Also fixed a (newly generated) warning

Warning (test-settings.R:108): it has a smart default for encodings
path[1]="dummy_packages/cp1252/R/metropolis-hastings-rho.R": No such file or directory
Backtrace:
 1. testthat::expect_identical(...)
      at test-settings.R:108:2
 6. lintr:::find_package(pkg_file)
 7. base::normalizePath(path)
      at lintr/R/settings_utils.R:7:2

Previously, existence of the path provided to lint_package() was never tested so it slipped by.

[codecov-commenter]

Codecov Report

Merging #1765 (f08409d) into main (f486464) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #1765   +/-   ##
=======================================
  Coverage   98.87%   98.87%           
=======================================
  Files         109      109           
  Lines        4622     4623    +1     
=======================================
+ Hits         4570     4571    +1     
  Misses         52       52           

Impacted Files	Coverage Δ
R/settings_utils.R	100.00% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[AshesITR]

@IndrajeetPatil there are currently 135 more undesirable_operator lints in this branch (ignoring the nolinted ones).
All of them lint a lintr::: expression in our test suite.
Maybe we should consider removing that one?

Note these are the only lints generated by withr::with_options(list(lintr.linter_file = ".lintr_new"), lint_package()) at the moment.

[IndrajeetPatil]

Maybe we should consider removing that one?

Definitely. We can add it back once #1692 is resolved.

Feel free to make the change in this PR.

[AshesITR]

Okay. Let's do that in a follow-up to keep this PR focused.

[IndrajeetPatil]

Nit: We don't need to include this. It is unnecessarily distracting.

[AshesITR]

removed. We can always recreate this if we want to.

[IndrajeetPatil]

Sorry for the misunderstanding.

I meant that we don't need that comment in the testthat.R file. It would still be good to have the testthat.R file without those comments. Otherwise, it'd be confusing to have tests without nothing executing those tests.

[IndrajeetPatil]

LGTM, thanks!

Just one nitpick, but I am fine either way it is resolved.