Compare case-insenitively for full cache key match (#303)

Some self-hosted (or otherwise non-github-hosted) runners are
non-case-preserving for cache keys. To support such configurations, set the
`cache-hit` output variable to `true` if the found cache key matches
case-insenitively.

Fixes: https://github.com/Swatinem/rust-cache/issues/302

dist/restore/index.js

@@ -151483,7 +151483,9 @@ async function run() {
             lookupOnly,
         });
         if (restoreKey) {
-            const match = restoreKey === key;
+            const match = restoreKey.localeCompare(key, undefined, {
+                sensitivity: "accent"
+            }) === 0;
             lib_core.info(`${lookupOnly ? "Found" : "Restored from"} cache key "${restoreKey}" full match: ${match}.`);
             if (!match) {
                 // pre-clean the target directory on cache mismatch