Add path filters to workflows to prevent unnecessary CI runs

[RAprogramm]

Add path filters to all workflows to run them only when relevant files change.

Problem

Currently all workflows run on EVERY push/PR, even when only documentation or workflow files change. This wastes CI resources and time.

Example: Changing .github/workflows/miri.yml triggers:

• Full CI (format, clippy, tests, coverage, benchmarks)
• Benchmark workflow
• All other workflows

This is illogical and inefficient.

Solution

Add path filters to workflows:

ci.yml - Run only when code changes

on:
  push:
    branches: [main]
    paths:
      - 'src/**'
      - 'tests/**'
      - 'benches/**'
      - 'examples/**'
      - 'Cargo.toml'
      - 'Cargo.lock'
      - '.rustfmt.toml'
      - '.github/workflows/ci.yml'
  pull_request:
    branches: [main]
    paths:
      - 'src/**'
      - 'tests/**'
      - 'benches/**'
      - 'examples/**'
      - 'Cargo.toml'
      - 'Cargo.lock'
      - '.rustfmt.toml'
      - '.github/workflows/ci.yml'

benchmark.yml - Run only when code or benchmarks change

on:
  push:
    branches: [main]
    paths:
      - 'src/**'
      - 'benches/**'
      - 'Cargo.toml'
      - 'Cargo.lock'
      - '.github/workflows/benchmark.yml'
  workflow_dispatch:

miri.yml - Run only when code changes

on:
  push:
    branches: [main]
    paths:
      - 'src/**'
      - 'tests/**'
      - 'Cargo.toml'
      - 'Cargo.lock'
      - '.github/workflows/miri.yml'
  pull_request:
    branches: [main]
    paths:
      - 'src/**'
      - 'tests/**'
      - 'Cargo.toml'
      - 'Cargo.lock'
      - '.github/workflows/miri.yml'
  schedule:
    - cron: '0 3 * * 1'

codeql.yml - Run only when code changes

on:
  push:
    branches: [main]
    paths:
      - 'src/**'
      - 'tests/**'
      - 'Cargo.toml'
      - '.github/workflows/codeql.yml'
  pull_request:
    branches: [main]
    paths:
      - 'src/**'
      - 'tests/**'
      - 'Cargo.toml'
      - '.github/workflows/codeql.yml'
  schedule:
    - cron: '0 0 * * 1'

release.yml - No changes needed

Already runs only on tags (v*..)

Benefits

• Saves CI minutes (no unnecessary runs)
• Faster workflow execution (no queuing)
• Logical workflow triggers
• Better resource utilization
• Professional CI/CD setup

Edge Cases

• workflow_dispatch still allows manual runs
• schedule triggers remain unchanged
• Each workflow includes its own .yml file in paths to run when workflow itself changes

Success Criteria

• All workflows have appropriate path filters
• README/docs changes do not trigger CI
• Workflow changes trigger only that specific workflow
• Code changes trigger all relevant workflows