style: fix hanging indent in helper-fixtures.R

lintr's indentation_linter flagged three continuation lines that were
indented one space too many (29 instead of 28, and 30 instead of 29).
Corrected to align exactly with the opening parenthesis of each call.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: billdenney

tests/testthat/helper-fixtures.R

@@ -1,7 +1,7 @@
 # Minimal fixture CT table for unit tests — does not load package data
 make_ct_fixture <- function(n_terms = 5L,
-                             valid_from = as.Date("2024-03-29"),
-                             valid_to   = as.Date(NA)) {
+                            valid_from = as.Date("2024-03-29"),
+                            valid_to   = as.Date(NA)) {
   data.frame(
     codelist_code  = "C66731",
     codelist_name  = "SEX",
@@ -21,8 +21,8 @@ make_ct_fixture <- function(n_terms = 5L,
 # Fixture with two CT versions: an old row closed out and a new replacement
 make_versioned_ct_fixture <- function() {
   old_row <- make_ct_fixture(n_terms = 2L, valid_from = as.Date("2023-09-29"),
-                              valid_to = as.Date("2024-03-28"))
+                             valid_to = as.Date("2024-03-28"))
   new_row <- make_ct_fixture(n_terms = 3L, valid_from = as.Date("2024-03-29"),
-                              valid_to = as.Date(NA))
+                             valid_to = as.Date(NA))
   rbind(old_row, new_row)
 }