Try this?

.github/workflows/deploy-bookdown-netlify.yml

@@ -18,11 +18,18 @@ jobs:
 
       - name: Set up R
         uses: r-lib/actions/setup-r@v2
+
+      - name: Install R dependencies with RSPM for dummies and GitHub PAT
+        run: |
+          # Set CRAN as the default repository
+          Rscript -e 'options(repos = c(CRAN = "https://cloud.r-project.org"))'
+          
+          # Install dummies from RSPM (archived version)
+          Rscript -e 'install.packages("dummies", repos = "https://packagemanager.rstudio.com/cran/__linux__/focal/2021-07-01")'
 
-      - name: Install R dependencies with GitHub PAT
-        uses: r-lib/actions/setup-r-dependencies@v2
-        env:
-          GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
+          # Install other dependencies from DESCRIPTION using GitHub PAT
+          Rscript -e 'Sys.setenv(GITHUB_PAT = Sys.getenv("GITHUB_TOKEN"))'
+          Rscript -e 'remotes::install_deps()'
 
       - name: Build bookdown site
         run: |

DESCRIPTION

@@ -43,6 +43,5 @@ Imports:
     tidytext
 Remotes: 
     data-edu/dataedu
-    cran/dummies
 Encoding: UTF-8
 LazyData: true