Add cflinuxfs5 support to install_go.sh

Drop cflinuxfs3 from the stack allowlist, update Go from 1.22.5 to
1.25.6, and use the cflinuxfs4 binary with a cflinuxfs5 fallback.
This matches the pattern already used by nodejs, ruby, go, python,
staticfile, dotnet-core, and nginx buildpacks.

When deploying via git URL, CF runs bin/supply as a shell script which
sources scripts/install_go.sh to bootstrap Go compilation. The stack
check only allowed cflinuxfs3 and cflinuxfs4, causing cflinuxfs5
deployments to fail with 'Unsupported stack'.

Author: tnikolova82

scripts/install_go.sh

@@ -5,24 +5,27 @@ set -u
 set -o pipefail
 
 function main() {
-  if [[ "${CF_STACK:-}" != "cflinuxfs3" && "${CF_STACK:-}" != "cflinuxfs4" ]]; then
+  if [[ "${CF_STACK:-}" != "cflinuxfs4" && "${CF_STACK:-}" != "cflinuxfs5" ]]; then
     echo "       **ERROR** Unsupported stack"
     echo "                 See https://docs.cloudfoundry.org/devguide/deploy-apps/stacks.html for more info"
     exit 1
   fi
 
   local version expected_sha dir
-  version="1.22.5"
-  expected_sha="ddb12ede43eef214c7d4376761bd5ba6297d5fa7a06d5635ea3e7a276b3db730"
+  version="1.25.6"
+  expected_sha="0ed64e3b9cb9b1c2ec57880dae2427b0ee2676f2ae2fb53c2e1bb838c500f9fb"
   dir="/tmp/go${version}"
 
   mkdir -p "${dir}"
 
   if [[ ! -f "${dir}/bin/go" ]]; then
-    local url
-    # TODO: use exact stack based dep, after go buildpack has cflinuxfs4 support
-    #url="https://buildpacks.cloudfoundry.org/dependencies/go/go_${version}_linux_x64_${CF_STACK}_${expected_sha:0:8}.tgz"
-    url="https://buildpacks.cloudfoundry.org/dependencies/go/go_${version}_linux_x64_cflinuxfs3_${expected_sha:0:8}.tgz"
+    local url stack_for_download
+    # Use cflinuxfs4 binary for cflinuxfs5 (compatible)
+    stack_for_download="${CF_STACK}"
+    if [[ "${CF_STACK}" == "cflinuxfs5" ]]; then
+      stack_for_download="cflinuxfs4"
+    fi
+    url="https://buildpacks.cloudfoundry.org/dependencies/go/go_${version}_linux_x64_${stack_for_download}_${expected_sha:0:8}.tgz"
 
     echo "-----> Download go ${version}"
     curl "${url}" \