GH-46442: [R] hms::as_hms tests fail on some of our crossbow builds (#46443)

### Rationale for this change

New functionality breaks tests with minimal builds

### What changes are included in this PR?

Skip tests on those builds

### Are these changes tested?

Updates are to tests

### Are there any user-facing changes?

No
* GitHub Issue: #46442

Authored-by: Nic Crane <thisisnic@gmail.com>
Signed-off-by: Nic Crane <thisisnic@gmail.com>

Author: thisisnic

r/tests/testthat/test-dplyr-funcs-datetime.R

@@ -3764,7 +3764,6 @@ test_that("hms::hms", {
     call_binding("hms::hms", seconds = NA),
     regexp = "All arguments must be numeric or NA_real_"
   )
-
 })
 
 test_that("hms::as_hms", {
@@ -3773,13 +3772,12 @@ test_that("hms::as_hms", {
     int = c(30L, 75L),
     integerish_dbl = c(31, 76),
     dbl = c(31.2, 76.4),
-    datetime = as.POSIXct(c(1645243500, 1745243500), tz = "UTC")
+    datetime = as.POSIXct(c(1645243500, 1745243500), tz = "UTC", origin = "1970-01-01")
   )
 
   compare_dplyr_binding(
     .input %>%
       mutate(
-        x = hms::as_hms(hms_string),
         x2 = hms::as_hms(int),
         x3 = hms::as_hms(integerish_dbl),
         x4 = hms::as_hms(datetime)
@@ -3792,4 +3790,15 @@ test_that("hms::as_hms", {
     arrow_table(test_df) %>% mutate(y = hms::as_hms(dbl)) %>% collect(),
     "was truncated converting to int32"
   )
+
+  skip_if_not_available("utf8proc")
+
+  compare_dplyr_binding(
+    .input %>%
+      mutate(
+        x = hms::as_hms(hms_string),
+      ) %>%
+      collect(),
+    test_df
+  )
 })