do not install from "source"

hopefully fixes "Error in curl::curl_fetch_memory(url, handle = handle) : : next InitializeSecurityContext failed: SEC_E_ILLEGAL_MESSAGE (0x80090326) - This error usually occurs when a fatal SSL/TLS alert is received (e.g. handshake failed)." (https://github.com/KWB-R/kwb.geosalz/actions/runs/3263114575/jobs/5362680759#step:11:287) during pkgdown "NEWS" build

.github/workflows/pkgdown.yaml

@@ -63,7 +63,6 @@ jobs:
         run: |
           remotes::install_deps(dependencies = TRUE)
           install.packages("pkgdown", type = "binary")
-          install.packages("RCurl", type = "source")
           RCurl::curlVersion()
         shell: Rscript {0}