By Dan Weil Adobe shares have slid sharply since the graphics-software specialist said Sept. 15 that it has agreed to buy Figma for about $20 billion. Investor Cathie Wood, chief executive of Ark Investment Management, has taken advantage of Adobe’s (ADBE) – Get Adobe Inc. Report stock plunge to snap up some shares. On Monday, Ark Next Generation Internet ETF (ARKW) – Get ARK Next Generation Internet ETF Report bought 23,605 shares of the design software titan, valued at $6.7 million as of Monday’s close. That follows the fund’s purchase of 22,874 shares on Sept. 19, valued at $4.5 million as …