chore: fix some minor issues in comments (#3304)

Author: criciss

block/internal/cache/generic_cache.go

@@ -102,7 +102,7 @@ func (c *Cache) setSeenBatch(hashes []string, height uint64) {
 		return
 	}
 
-	// currently not used, but there for compleness against setSeen
+	// currently not used, but there for completeness against setSeen
 	for _, h := range hashes {
 		if existing, ok := c.hashByHeight[height]; ok && existing == h {
 			c.hashes[existing] = true

block/internal/cache/generic_cache_test.go

@@ -297,7 +297,7 @@ func TestHeightPlaceholderKey(t *testing.T) {
 // TestCache_NoPlaceholderLeakAfterRefire verifies that when the DA retriever
 // re-fires setDAIncluded with the real content hash after a restart, the
 // snapshot placeholder that RestoreFromStore installed is evicted from
-// daIncluded.  Without the eviction in setDAIncluded, every restart cycle
+// daIncluded. Without the eviction in setDAIncluded, every restart cycle
 // would leak one orphaned placeholder key per in-flight block.
 func TestCache_NoPlaceholderLeakAfterRefire(t *testing.T) {
 	st := testMemStore(t)