copilot-theorem: Remove unused pragmas. Refs #613.

[carte731]

Remove unused pragmas from copilot-theorem and update the changed logs, as prescribed in the solution proposed for #613.

This PR is a continuation of #630.

[ivanperez-keera]

Change Manager: Verified that:

• Solution is implemented:
  • The code proposed compiles and passes all tests. Details:
    Build log: https://app.travis-ci.com/github/Copilot-Language/copilot/builds/275653840
  • The solution proposed produces the expected result. Details:
    The following dockerfile runs hlint on copilot-theorem with the provided list of ignored warnings, which does not include unnecessary language pragmas, and checks that there are no warnings reported, after which it prints the message success:

    --- Dockerfile-verify-613
    FROM ubuntu:jammy
    
    ENV DEBIAN_FRONTEND=noninteractive
    
    RUN apt-get update
    
    RUN apt-get install --yes git
    RUN apt-get install --yes hlint
    
    ADD ignore.yaml /tmp/ignore.yaml
    
    RUN hlint --version
    
    SHELL ["/bin/bash", "-c"]
    CMD git clone $REPO \
        && cd $NAME \
        && git checkout $COMMIT \
        && hlint -h /tmp/ignore.yaml copilot-theorem/src \
        && echo "Success"
    
    --- ignore.yaml
    - ignore: {name: "Redundant bracket"}
    - ignore: {name: "Use infix"}
    - ignore: {name: "Redundant as"}
    - ignore: {name: "Redundant <$>"}
    - ignore: {name: "Use camelCase"}
    - ignore: {name: "Avoid lambda"}
    - ignore: {name: "Use gets"}
    - ignore: {name: "Redundant $"}
    - ignore: {name: "Use <&>"}
    - ignore: {name: "Use concatMap"}
    - ignore: {name: "Move brackets to avoid $"}
    - ignore: {name: "Use /="}
    - ignore: {name: "Use newtype instead of data"}
    - ignore: {name: "Use :"}
    - ignore: {name: "Replace case with fromMaybe"}
    - ignore: {name: "Use >=>"}
    - ignore: {name: "Use curry"}
    - ignore: {name: "Use first"}
    - ignore: {name: "Use hPrint"}
    - ignore: {name: "Use or"}
    - ignore: {name: "Use fmap"}
    - ignore: {name: "Use if"}
    - ignore: {name: "Use <$>"}
    - ignore: {name: "Reduce duplication"}
    - ignore: {name: "Eta reduce"}
    

    Command (substitute variables based on new path after merge):

    $ docker run -e REPO=https://github.com/carte731/copilot -e NAME=copilot -e COMMIT=c9954d663f2988b2db9bd8ce65f9f14e71512195 copilot-verify-613
    

• Implementation is documented. Details:
  No updates needed; the PR removes pragmas but does not otherwise alter or add code.
• Change history is clear.
• Commit messages are clear.
• Changelogs are updated.
• Examples are updated. Details:
  No updates needed; the PR removes pragmas but does not otherwise alter or add code, nor are examples affected.
• Author is internal or has provided signed CLA.
• Required version bumps are evaluated. Details:
  Bump not needed; change removes pragmas but does not affect the public API.