theme: Add file icon associations for .rdata and .RData files (#24925)

.RData is a file that stores R objects.

Release Notes:

- Added file icon associations for `.rdata` and `.RData` files.

---------

Co-authored-by: Marshall Bowers <git@maxdeviant.com>

crates/theme/src/icon_theme.rs

@@ -195,7 +195,8 @@ const FILE_SUFFIXES_BY_ICON_KEY: &[(&str, &[&str])] = &[
         "storage",
         &[
             "accdb", "csv", "dat", "db", "dbf", "dll", "fmp", "fp7", "frm", "gdb", "ib", "jsonc",
-            "ldf", "mdb", "mdf", "myd", "myi", "pdb", "sav", "sdf", "sql", "sqlite", "tsv",
+            "ldf", "mdb", "mdf", "myd", "myi", "pdb", "RData", "rdata", "sav", "sdf", "sql",
+            "sqlite", "tsv",
         ],
     ),
     (