Update Dockerfile files

[phansys]

The Dockerfile files were updated with the following changes:

• Defined version constraints for bundler and rubocop in order to fix dependency resolution at Dockerfile-dev

  Show dependency resolution issue

  $ docker build --file Dockerfile-dev --tag cfn_nag:latest .
  [+] Building 136.8s (8/10)                                                                                                                                                                                                     docker:default
   => [internal] load build definition from Dockerfile-dev                                                                                                                                                                                 0.0s
   => => transferring dockerfile: 196B                                                                                                                                                                                                     0.0s
   => [internal] load metadata for docker.io/library/ruby:2.7-alpine                                                                                                                                                                       1.8s
   => [internal] load .dockerignore                                                                                                                                                                                                        0.0s
   => => transferring context: 2B                                                                                                                                                                                                          0.0s
   => [internal] load build context                                                                                                                                                                                                        0.1s
   => => transferring context: 346.58kB                                                                                                                                                                                                    0.1s
   => CACHED [1/6] FROM docker.io/library/ruby:2.7-alpine@sha256:371668748735a808d1fd1c506878e09f40cb542ffc758cfa7eb124f90827e8d9                                                                                                          0.0s
   => [2/6] COPY . /                                                                                                                                                                                                                       0.2s
   => [3/6] RUN apk add --update build-base     curl     git                                                                                                                                                                               8.3s
   => ERROR [4/6] RUN gem install bundler                                                                                                                                                                                                126.2s
  ------                                                                                                                                                                                                                                        
   > [4/6] RUN gem install bundler:                                                                                                                                                                                                             
  126.0 ERROR:  Error installing bundler:                                                                                                                                                                                                       
  126.0   The last version of bundler (>= 0) to support your Ruby & RubyGems was 2.4.22. Try installing it with `gem install bundler -v 2.4.22`                                                                                                 
  126.0   bundler requires Ruby version >= 3.0.0. The current ruby version is 2.7.8.225.                                                                                                                                                        
  ------
  Dockerfile-dev:9
  --------------------
     7 |         git
     8 |     
     9 | >>> RUN gem install bundler
    10 |     RUN gem install rubocop
    11 |     RUN bundle install
  --------------------
  ERROR: failed to solve: process "/bin/sh -c gem install bundler" did not complete successfully: exit code: 1
  

• Combined all the executed commands into a single RUN instruction to reduce the number of image layers

• Added --no-cache option to apk add invocation to reduce image size

• Added the syntax parser directive to declare the Dockerfile syntax version to use for the build

• Added labels with pre-defined annotation keys from the OpenContainers Annotations Spec