add_shadow() no longer rescales shadow matrix when original hillshade is rescaled via add_overlay() [BUG]

[apsteinmetz]

Describe the bug
I have an image overlay with different dimensions than my elevation matrix. I want add_overlay() to rescale the original elevation matrix. If I add a shadowmap created from the original elevation matrix the shadowmap is NOT rescaled to match the hillshade (the docs say rescaling is the default) but instead throws a "Not a Matrix" error. This is a new error on code that used to work (a year ago).

Reproducible Example

dim(elev_matrix)
# [1]  755 1774
dim(gwl_png)
# [1] 3549 1510    3

# this works
gwl <- elev_matrix |>
  sphere_shade() |>
  add_overlay(gwl_png, rescale_original = FALSE) |>
  add_shadow(lamb_shade(elev_matrix))

# this works
gwl <- elev_matrix |>
  sphere_shade() |>
  add_overlay(gwl_png, rescale_original = TRUE)

# this does NOT work
gwl <- elev_matrix |>
  sphere_shade() |>
  add_overlay(gwl_png, rescale_original = TRUE) |>
  add_shadow(lamb_shade(elev_matrix))

# Error: Not a matrix.

**Session Info**
Include the output of the `sessionInfo()` function here. Issues will be closed without providing this as a minimum.

> sessionInfo()
R version 4.3.0 (2023-04-21 ucrt)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 11 x64 (build 22631)

Matrix products: default


locale:
[1] LC_COLLATE=English_United States.utf8  LC_CTYPE=English_United States.utf8    LC_MONETARY=English_United States.utf8 LC_NUMERIC=C                          
[5] LC_TIME=English_United States.utf8    

time zone: America/New_York
tzcode source: internal

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
 [1] lubridate_1.9.3  forcats_1.0.0    stringr_1.5.1    dplyr_1.1.4      purrr_1.0.2      readr_2.1.5      tidyr_1.3.1      tibble_3.2.1     ggplot2_3.5.1    tidyverse_2.0.0 
[11] maptiles_0.8.0   osrm_4.2.0       smoothr_1.0.1    raster_3.6-30    sp_2.1-4         terra_1.7-83     sf_1.0-19        png_0.1-8        elevatr_0.99.0   rayshader_0.37.3

loaded via a namespace (and not attached):
 [1] DBI_1.2.3             httr2_1.0.6           rlang_1.1.4           magrittr_2.0.3        e1071_1.7-16          compiler_4.3.0        callr_3.7.6          
 [8] vctrs_0.6.5           pkgconfig_2.0.3       crayon_1.5.3          fastmap_1.2.0         magick_2.8.5          utf8_1.2.4            promises_1.3.0       
[15] tzdb_0.4.0            ps_1.8.1              chattr_0.2.0.9000     xfun_0.49             cachem_1.1.0          jsonlite_1.8.9        progress_1.2.3       
[22] later_1.3.2           rayimage_0.11.0       parallel_4.3.0        prettyunits_1.2.0     R6_2.5.1              bslib_0.8.0           stringi_1.8.4        
[29] extrafontdb_1.0       pkgload_1.4.0         jquerylib_0.1.4       Rcpp_1.0.13-1         iterators_1.0.14      knitr_1.49            base64enc_0.1-3      
[36] extrafont_0.19        httpuv_1.6.15         timechange_0.3.0      tidyselect_1.2.1      rstudioapi_0.17.1     yaml_2.3.10           RcppSimdJson_0.1.12  
[43] doParallel_1.0.17     codetools_0.2-19      curl_6.0.0            processx_3.8.4        lattice_0.21-8        shiny_1.9.1           withr_3.0.2          
[50] evaluate_1.0.1        units_0.8-5           proxy_0.4-27          isoband_0.2.7         pillar_1.9.0          KernSmooth_2.23-20    foreach_1.5.2        
[57] googlePolylines_0.8.5 generics_0.1.3        mapiso_0.3.0          hms_1.1.3             munsell_0.5.1         scales_1.3.0          xtable_1.8-4         
[64] class_7.3-21          glue_1.8.0            clipr_0.8.0           tools_4.3.0           fs_1.6.5              rgl_1.3.12            grid_4.3.0           
[71] slippymath_0.3.1      Rttf2pt1_1.3.12       colorspace_2.1-1      cli_3.6.2             rappdirs_0.3.3        fansi_1.0.6           gtable_0.3.6         
[78] sass_0.4.9            digest_0.6.37         progressr_0.15.0      classInt_0.4-10       htmlwidgets_1.6.4     htmltools_0.5.8.1     lifecycle_1.0.4      
[85] httr_1.4.7            mime_0.12