chore: upgrade Node.js version in lambda

# Why
Node.js v18 is going EoL in September

Author: bripkens

packages/otelbin-validation-image/Dockerfile

@@ -24,7 +24,7 @@ ADD ./rpm_download.sh /usr/app/rpm_download.sh
 
 RUN /usr/app/rpm_download.sh
 
-FROM public.ecr.aws/lambda/nodejs:18 AS builder
+FROM public.ecr.aws/lambda/nodejs:20 AS builder
 
 WORKDIR /usr/app
 COPY package.json package.json
@@ -40,7 +40,7 @@ RUN unzip 0.6.0.zip
 WORKDIR /go/opentelemetry-lambda-layer-collector-0.6.0/collector
 RUN make package
 
-FROM public.ecr.aws/lambda/nodejs:18
+FROM public.ecr.aws/lambda/nodejs:20
 
 # Install useradd command needed by the OtelContrib RPM
 WORKDIR /tmp