CI: stop running coverage on every PR/push

As the activity on proof-systems have been increasing drastically recently, we
noticed that the code coverage can be causing some issues, and also causes our
productive to be slower as we need to wait more.

We already running the code coverage on nightly, see ci-nightly.yml

.github/workflows/ci.yml

@@ -66,12 +66,7 @@ jobs:
 
   run_checks:
     name: Run checks and tests
-    # We run only one of the matrix options on the toffee `hetzner-1` self-hosted GitHub runner.
-    # Only in this configuration we enable tests with the code coverage data gathering.
-    # runs-on: [hetzner-proof-systems-runners-group-1]
-    runs-on: ${{ matrix.rust_toolchain_version == '1.74' && 'hetzner-1' || 'ubuntu-latest' }}
-    env:
-      RUST_TOOLCHAIN_COVERAGE_VERSION: "1.74"
+    runs-on: 'ubuntu-latest'
     strategy:
       matrix:
         rust_toolchain_version: ["1.72", "1.73", "1.74", "1.75", "1.76", "1.77", "1.78", "1.79"]
@@ -162,31 +157,11 @@ jobs:
         uses: ./.github/actions/build-mips
 
       - name: Doc tests
-        if: ${{ matrix.rust_toolchain_version != env.RUST_TOOLCHAIN_COVERAGE_VERSION }}
         run: |
           eval $(opam env)
           make test-doc
 
       - name: Run non-heavy tests without the code coverage
-        if: ${{ matrix.rust_toolchain_version != env.RUST_TOOLCHAIN_COVERAGE_VERSION }}
         run: |
           eval $(opam env)
           make nextest
-
-      - name: Run non-heavy tests with the code coverage
-        if: ${{ matrix.rust_toolchain_version == env.RUST_TOOLCHAIN_COVERAGE_VERSION }}
-        run: |
-          eval $(opam env)
-          make nextest-with-coverage
-          make test-doc-with-coverage
-          make generate-test-coverage-report
-
-      - name: Use shared code coverage summary
-        if: ${{ matrix.rust_toolchain_version == env.RUST_TOOLCHAIN_COVERAGE_VERSION }}
-        uses: ./.github/actions/coverage-summary-shared
-
-      - name: Use shared Codecov reporting steps
-        if: ${{ matrix.rust_toolchain_version == env.RUST_TOOLCHAIN_COVERAGE_VERSION }}
-        uses: ./.github/actions/codecov-shared
-        with:
-          token: ${{ secrets.CODECOV_TOKEN }}