Github Actions: eliminate cache

I had hoped that storing kernel and debuginfo RPMs in a cache would
improve the runtime of the actions by reducing the amount of downloads.
But I haven't seen much in the way of improvement on the runtime when
the cache was working, and the cache has caused *several* failures for
pull requests and CI. Most developers don't have push access and
therefore can't use the "re-run job" button. It seems like the cache
just isn't helping, so let's get rid of it.

Signed-off-by: Stephen Brennan <[email protected]>

Author: brenns10

.github/workflows/litevm.yml

@@ -63,32 +63,6 @@ jobs:
           tox list
           tox --notest
           tox -e runner --notest
-
-      # Use Github Actions to cache RPMs by date. This can save a couple minutes
-      # in the run, which is nice. The cache contains the Yum sqlite database,
-      # and the downloaded RPMs.
-      #
-      # A cache miss results in getting the most recent cached data (e.g. from
-      # yesterday). The runner will check the repo metadata and get the updated
-      # data, and delete any stale data, so after the run completes, the
-      # testdata can be cached for future runs.
-      #
-      # On a cache hit, the test runner will still check the yum repo metadata,
-      # and if it differs from the cached data, it will clear and download it.
-      # So a cache hit isn't guaranteed to speed things up, but kernel packages
-      # aren't usually updated _that_ frequently.
-      - name: Get Date
-        id: get-date
-        run: |
-          echo "date=$(/bin/date -u "+%Y%m%d")" >> $GITHUB_OUTPUT
-        shell: bash
-      - name: Cache RPMs
-        uses: actions/cache@v3
-        with:
-          path: testdata/yumcache
-          key: ${{ runner.os }}-rpms-${{ steps.get-date.outputs.date }}
-          restore-keys: |
-            ${{ runner.os }}-rpms-
       - name: Fetch RPMs
         run: |
           tox -e runner -- python -m testing.litevm.rpm