GH-49459: [R][CI] Use RHEL-9 binaries on Amazon Linux 2023 builds (#49460)

### Rationale for this change

It takes 45 mins to install the duckdb R package in the benchmarks as it builds from source

### What changes are included in this PR?

Use the RSPM RHEL9 binaries instead by mapping Amazon Linux 2023 to RHEL9

### Are these changes tested?

I did locally but I'll ask Ursabot to benchmark or whatever

### Are there any user-facing changes?

Nah
* GitHub Issue: #49459

Authored-by: Nic Crane <thisisnic@gmail.com>
Signed-off-by: Raúl Cumplido <raulcumplido@gmail.com>

Author: thisisnic

ci/etc/rprofile

@@ -4,7 +4,9 @@ local({
     rspm_template <- "https://packagemanager.rstudio.com/cran/__linux__/%s/latest"
     # See https://github.com/rstudio/r-docker#releases-and-tags,
     # but note that RSPM still uses "centos8"
-    supported_os <- c("bionic", "focal", "jammy", "centos7", "centos8", "opensuse153")
+    supported_os <- c("bionic", "focal", "jammy", "centos7", "centos8", "opensuse153", "rhel9")
+    # Amazon Linux 2023 is compatible with RHEL 9 binaries
+    amzn_to_rhel <- c("2023" = "rhel9")
 
     if (nzchar(Sys.which("lsb_release"))) {
       os <- tolower(system("lsb_release -cs", intern = TRUE))
@@ -28,6 +30,13 @@ local({
             return(sprintf(rspm_template, os))
           }
         }
+        # Amazon Linux: map to compatible RHEL version
+        if (gsub('"', '', vals["ID"]) == "amzn") {
+          version <- gsub('"', '', vals["VERSION_ID"])
+          if (version %in% names(amzn_to_rhel)) {
+            return(sprintf(rspm_template, amzn_to_rhel[version]))
+          }
+        }
       }
     }
     if (file.exists("/etc/system-release")) {