fix: typo in files regex

Co-authored-by: Lorenz Walthert <[email protected]>

Author: jcken95

.pre-commit-hooks.yaml

@@ -110,7 +110,7 @@
     description: check if a `.R` file is lint free (using {lintr})
     entry: Rscript inst/hooks/exported/lintr.R
     language: r
-    files: '(\.[rR]profile|\.R|\.Rmd|\.Rnw|\.r|\.rmd|\.rnw\.[qQ]md)$'
+    files: '(\.[rR]profile|\.R|\.Rmd|\.Rnw|\.r|\.rmd|\.rnw|\.[qQ]md)$'
     exclude: 'renv/activate\.R'
     minimum_pre_commit_version: "2.13.0"
 -   id: pkgdown