GitHub action setup-r-dependencies fails stating there is no package called 'digest'

I've been trying to set up some GitHub actions to automatically check my R package and run test coverage. I am currently using the action setup-r-dependencies@v2 to install the dependencies but it is failing to install the package 'digest'. Returning the following error:

 Error: Error: <callr_remote_error: Cannot install packages:
  * deps::.: there is no package called ‘digest’>
   in process 8254 
  -->
  <simpleError: Cannot install packages:
  * deps::.: there is no package called ‘digest’>

The dependencies in the package are as follows:

Imports:
    assertthat,
    crayon,
    forcats,
    rmarkdown,
    purrr,
    ggplot2,
    htmltools,
    lubridate,
    dplyr,
    tidyselect,
    rlang,
    INLA,
    arm,
    magrittr,
    glue,
    googleAuthR,
    googleCloudStorageR,
    stringr

Finally, the workflow itself that is failing looks like this (taken from the tidyverse packages):

on:
  push:
    branches: [main, dev]
  pull_request:
    branches: [main, dev]

name: test-coverage

jobs:
  test-coverage:
    runs-on: ubuntu-latest
    env:
      GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}

    steps:
      - uses: actions/checkout@v3
      
      - name: Set up R 
        uses: r-lib/actions/setup-r@v2
        with:
          use-public-rspm: true

      - name: Install dependencies
        uses: r-lib/actions/setup-r-dependencies@v2
        with:
          extra-packages: any::covr
          needs: coverage

      - name: Test coverage
        run: covr::codecov(quiet = FALSE)
        shell: Rscript {0}

I have this same workflow working in another package and covr depends on digest which is getting installed in that package workflow. I'm left thinking that it must be to do with the package imports but I can't figure it out and would appreciate any help.

Not all of these packages are listed on CRAN.