[sqlite] Investigate the cause of SqliteBusy error in tests (currently ignored)

This was introduced since #24.
- In this PR, I bumped deno-sqlite from d451a28e55180730a296a9383cd5dd26155a2c11 to 73935087a1ebe9108d784503bc5474662ba54b73.
  - dyedgreen/deno-sqlite@d451a28...7393508

  1) query builder > sub-query
       "after all" hook for "should execute sub query in joins as string (as selection)":
     SqliteError: unable to close due to unfinalized statements or unfinished backups
      at DB._error (https://deno.land/x/sqlite@73935087a1ebe9108d784503bc5474662ba54b73/src/db.js:265:16)
      at DB.close (https://deno.land/x/sqlite@73935087a1ebe9108d784503bc5474662ba54b73/src/db.js:242:18)
      at SqliteDriver.disconnect (SqliteDriver.ts:53:33)
      at Connection.close (Connection.ts:223:27)
      at test-utils.ts:278:104
      at Array.map (<anonymous>)
      at closeTestingConnections (test-utils.ts:278:36)
      at Context.<anonymous> (query-builder-subquery.ts:24:17)
      at callFn (https://unpkg.com/mocha@7.0.0/mocha.js:5420:21)
      at Hook.Runnable.run (https://unpkg.com/mocha@7.0.0/mocha.js:5407:7)

typeorm/src/driver/sqlite/SqliteDriver.ts

Lines 56 to 63 in a238578

    
           if (error.code === 5) { // SqliteBusy 
        
               // FIXME 
        
               // This problem occurs since deno-sqlite@73935087a1ebe9108d784503bc5474662ba54b73. 
        
               // We need more research... 
        
               console.warn(error); // this.connection.logger.log("warn", error.message); 
        
           } else { 
        
               throw error; 
        
           }

	if (error.code === 5) { // SqliteBusy
	// FIXME
	// This problem occurs since deno-sqlite@73935087a1ebe9108d784503bc5474662ba54b73.
	// We need more research...
	console.warn(error); // this.connection.logger.log("warn", error.message);
	} else {
	throw error;
	}