feat: Be more generous with marking contacts as verified for now (#7336)

Context: PR #7116 is backwards-incompatible with versions older than
v2.21, and since the release hasn't reached all users yet, we currently
can't release from main; for details see #7326.

Issue #7326 explains how we can make this less breaking, but this only
works if many contacts are verified. So, this PR here proposes to
postpone the stricter rules for who is verified a bit:

- Set verification timeout for invite codes to 1 week (this is still
stricter than no timeout at all, which we had in the past)
- Don't reset indirect verifications yet

In a few months (when everyone has v2.22.0), we can revert the PR here,
then.

---------

Co-authored-by: l <link2xt@testrun.org>

src/sql/migrations.rs

@@ -1261,15 +1261,7 @@ CREATE INDEX gossip_timestamp_index ON gossip_timestamp (chat_id, fingerprint);
         .await?;
     }
 
-    inc_and_check(&mut migration_version, 134)?;
-    if dbversion < migration_version {
-        // Reset all indirect verifications.
-        sql.execute_migration(
-            "UPDATE contacts SET verifier=0 WHERE verifier!=1",
-            migration_version,
-        )
-        .await?;
-    }
+    inc_and_check(&mut migration_version, 134)?; // Migration 134 was removed
 
     inc_and_check(&mut migration_version, 135)?;
     if dbversion < migration_version {