build: simplify release notes as cross-platform (#13054)

Signed-off-by: Anton Gilgur <agilgur5@gmail.com>

Makefile

@@ -757,7 +757,7 @@ pre-commit: codegen lint docs
 # release
 
 release-notes: /dev/null
-	version=$(VERSION) envsubst < hack/release-notes.md > release-notes
+	version=$(VERSION) envsubst '$$version' < hack/release-notes.md > release-notes
 
 .PHONY: checksums
 checksums:

hack/release-notes.md

@@ -12,43 +12,28 @@ Check the [upgrading guide](https://argo-workflows.readthedocs.io/en/latest/upgr
 
 ### CLI
 
-#### Mac
+#### Mac / Linux
 
 Available via `curl`
 
 ```bash
-# Download the binary
-curl -sLO https://github.com/argoproj/argo-workflows/releases/download/${version}/argo-darwin-amd64.gz
-
-# Unzip
-gunzip argo-darwin-amd64.gz
-
-# Make binary executable
-chmod +x argo-darwin-amd64
-
-# Move binary to path
-mv ./argo-darwin-amd64 /usr/local/bin/argo
+# Detect OS
+ARGO_OS="darwin"
+if [[ uname -s != "Darwin" ]]; then
+  ARGO_OS="linux"
+fi
 
-# Test installation
-argo version
-```
-
-#### Linux
-
-Available via `curl`
-
-```bash
 # Download the binary
-curl -sLO https://github.com/argoproj/argo-workflows/releases/download/${version}/argo-linux-amd64.gz
+curl -sLO "https://github.com/argoproj/argo-workflows/releases/download/$version/argo-$ARGO_OS-amd64.gz"
 
 # Unzip
-gunzip argo-linux-amd64.gz
+gunzip "argo-$ARGO_OS-amd64.gz"
 
 # Make binary executable
-chmod +x argo-linux-amd64
+chmod +x "argo-$ARGO_OS-amd64"
 
 # Move binary to path
-mv ./argo-linux-amd64 /usr/local/bin/argo
+mv "./argo-$ARGO_OS-amd64" /usr/local/bin/argo
 
 # Test installation
 argo version
@@ -58,5 +43,5 @@ argo version
 
 ```bash
 kubectl create namespace argo
-kubectl apply -n argo -f https://github.com/argoproj/argo-workflows/releases/download/${version}/install.yaml
+kubectl apply -n argo -f https://github.com/argoproj/argo-workflows/releases/download/$version/install.yaml
 ```