Migrate to arm64 arch, provided.al2 runtime

The previous go1.x runtime is deprecated, per:
- https://aws.amazon.com/blogs/compute/migrating-aws-lambda-functions-from-the-go1-x-runtime-to-the-custom-runtime-on-amazon-linux-2/

See also:
- https://aws.amazon.com/blogs/aws/update-on-amazon-linux-ami-end-of-life/
- https://docs.aws.amazon.com/lambda/latest/dg/runtime-support-policy.html

Makefile

@@ -8,9 +8,10 @@ SHELL := /bin/bash
 # https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/sam-cli-command-reference-sam-build.html#examples-makefile-identifier
 # https://docs.aws.amazon.com/lambda/latest/dg/golang-package.html
 # https://github.com/aws-samples/sessions-with-aws-sam/tree/master/go-al2
+# https://aws.amazon.com/blogs/compute/migrating-aws-lambda-functions-from-the-go1-x-runtime-to-the-custom-runtime-on-amazon-linux-2/
 build-Function:
-	GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build -ldflags="-s -w" \
-		-o $(ARTIFACTS_DIR)/elistman-lambda lambda/main.go
+	GOOS=linux GOARCH=arm64 CGO_ENABLED=0 go build -ldflags="-s -w" \
+		-tags lambda.norpc -o $(ARTIFACTS_DIR)/bootstrap lambda/main.go
 
 static-checks:
 	go vet -tags=all_tests ./...

template.yml

@@ -55,8 +55,11 @@ Resources:
       BuildMethod: makefile
     DependsOn: FunctionLogs
     Properties:
-      Handler: elistman-lambda
-      Runtime: go1.x
+      Handler: bootstrap
+      # https://aws.amazon.com/blogs/compute/migrating-aws-lambda-functions-from-the-go1-x-runtime-to-the-custom-runtime-on-amazon-linux-2/
+      Runtime: provided.al2
+      Architectures:
+      - "arm64"
       Description: Coordinates between the API Gateway, DynamoDB, SES, and SNS
       Timeout: 300
       FunctionName: !Sub "${AWS::StackName}-function"