NEWARK, California — Employers have decided to eliminate hundreds of biotech and tech jobs in the East Bay with layoffs at companies in Emeryville and Newark, a fresh round of unsettling job cuts during uncertain economic times. An estimated 254 jobs are being cut by the end of this year in the East Bay, according to official filings with the state Employment Development Department. Zymergen intends to eliminate 110 jobs at its main office in Emeryville, the WARN notice to the EDD stated. The Zymergen job cuts are slated to take place around Dec. 19. Astreya, which provides technology and soft…