Update taiki-e/install-action digest to 7fe7b8c (#358)

Author: nextest-bot

.github/workflows/ci.yml

@@ -25,7 +25,7 @@ jobs:
       - name: Lint (rustfmt)
         run: cargo xfmt --check
       - name: Install cargo readme
-        uses: taiki-e/install-action@d6d752794628f1e1fffa3c4d3c8874e06f043d50 # v2
+        uses: taiki-e/install-action@7fe7b8c79a3c5569643cf27dfc32456883a4cd4d # v2
         with:
           tool: cargo-readme
       - name: Run cargo readme