Selectively install packages. If it's already installed don't reinstall.

install.R

# Just copy paste your "library" statements here using {datapasta}:
packages <- c(
  "library(shiny)", "library(bs4Dash)", "library(shinyjs)", 
  "library(shinyWidgets)", "library(firebase)", "library(glue)", 
  "library(DBI)", "library(RPostgres)", "library(lubridate)", 
  "library(htmlwidgets)", "library(shinybusy)"
)

# rm "library()" leaving bare pkg chars:
pkg_nms <- gsub(pattern = "library\\(", replacement = "", x = packages) |> 
  gsub(pattern = "\\)", replacement = "")

# install the packages selectively:
for (package in pkg_nms) {
  # if pkg is not installed:
  if ( !(package %in% rownames(installed.packages())) ) {
    install.packages(package, repos='https://cloud.r-project.org/')
    cat('{', package, '} installed!\n', sep = '')
    next
  }
  
  # if pkg is already installed:
  cat('{', package, '} is already installed!\n', sep = '')
}