search: use v2 API
search: use v2 API

The v3 API currently lacks a search feature. Use the v2 API instead for
much faster pull request filtering.

Closes Homebrew/homebrew#9592.

Signed-off-by: Misty De Meo <85d6b3741948526aebc363d97f74b6575b2cc027@gmail.com>

alyssais/brew,mistydemeo/homebrew,DomT4/brew,Homebrew/brew,MikeMcQuaid/brew,gordonmcshane/homebrew,EricFromCanada/brew,mistydemeo/homebrew,sjackman/homebrew,Linuxbrew/brew,gordonmcshane/homebrew,zmwangx/brew,konqui/brew,mahori/brew,vitorgalvao/brew,aw1621107/brew,Homebrew/brew,toonetown/homebrew,MikeMcQuaid/brew,sjackman/homebrew,sjackman/homebrew,Linuxbrew/brew,muellermartin/dist,reelsense/brew,nandub/brew,MikeMcQuaid/brew,mgrimes/brew,DomT4/brew,mahori/brew,JCount/brew,maxim-belkin/brew,staticfloat/brew,AnastasiaSulyagina/brew,toonetown/homebrew,claui/brew,EricFromCanada/brew,MikeMcQuaid/brew,pseudocody/brew,AnastasiaSulyagina/brew,ilovezfs/brew,gordonmcshane/homebrew,maxim-belkin/brew,nandub/brew,bfontaine/brew,gregory-nisbet/brew,bfontaine/brew,claui/brew,claui/brew,gregory-nisbet/brew,JCount/brew,mgrimes/brew,alyssais/brew,rwhogg/brew,DomT4/brew,staticfloat/brew,tonyg/homebrew,nandub/brew,hanxue/linuxbrew,reelsense/brew,vitorgalvao/brew,amar-laksh/brew_sudo,DomT4/brew,rwhogg/brew,reelsense/brew,aw1621107/brew,reitermarkus/brew,reitermarkus/brew,ilovezfs/brew,EricFromCanada/brew,rwhogg/brew,hanxue/linuxbrew,amar-laksh/brew_sudo,nandub/brew,palxex/brew,tonyg/homebrew,vitorgalvao/brew,tonyg/homebrew,JCount/brew,amar-laksh/brew_sudo,reitermarkus/brew,mahori/brew,mgrimes/brew,mahori/brew,palxex/brew,bfontaine/brew,JCount/brew,jmsundar/brew,pseudocody/brew,jmsundar/brew,muellermartin/dist,palxex/brew,Homebrew/brew,konqui/brew,reitermarkus/brew,alyssais/brew,maxim-belkin/brew,Homebrew/brew,zmwangx/brew,AnastasiaSulyagina/brew,aw1621107/brew,claui/brew,konqui/brew,zmwangx/brew,Linuxbrew/brew,Linuxbrew/brew,konqui/brew,jmsundar/brew,sjackman/homebrew,toonetown/homebrew,ilovezfs/brew,gregory-nisbet/brew,pseudocody/brew,vitorgalvao/brew,muellermartin/dist,EricFromCanada/brew,mistydemeo/homebrew,hanxue/linuxbrew,staticfloat/brew