CI: Update some external GitHub Actions (#118)

Author: DilumAluthge

.github/workflows/ci.yml

@@ -23,12 +23,12 @@ jobs:
         arch:
           - x64
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v6
       - uses: julia-actions/setup-julia@v1
         with:
           version: ${{ matrix.version }}
           arch: ${{ matrix.arch }}
-      - uses: actions/cache@v1
+      - uses: actions/cache@v5
         env:
           cache-name: cache-artifacts
         with:
@@ -44,7 +44,7 @@ jobs:
         continue-on-error: ${{ matrix.version == 'nightly' }}
       - uses: julia-actions/julia-processcoverage@v1
         continue-on-error: ${{ matrix.version == 'nightly' }}
-      - uses: codecov/codecov-action@v1
+      - uses: codecov/codecov-action@v6
         continue-on-error: ${{ matrix.version == 'nightly' }}
         with:
-          file: lcov.info
+          file: lcov.info