fix: make AUR publishing fail gracefully

[barlevalon]

AUR can experience downtime, which currently blocks the entire release process. This PR wraps AUR publishing in try-catch to provide best-effort updates while ensuring releases can continue even when AUR is unavailable.

The AUR package will be updated when the service is available, but releases won't be blocked if it's down.

Fixes #2042

[warmwaffles]

Due to the latest downtime, I've resorted to simply bumping the PKGBUILD along with

updpkgsums
makepkg -sci

pkgname='opencode-bin'
pkgver=0.5.13
options=('!debug' '!strip')
pkgrel=1
pkgdesc='The AI coding agent built for the terminal.'
url='https://github.com/sst/opencode'
arch=('aarch64' 'x86_64')
license=('MIT')
provides=('opencode')
conflicts=('opencode')
depends=('fzf' 'ripgrep')

source_aarch64=("${pkgname}_${pkgver}_aarch64.zip::https://github.com/sst/opencode/releases/download/v${pkgver}/opencode-linux-arm64.zip")
sha256sums_aarch64=('bb147f39a06c988d8c76acb7ff88efdf2153d058d824dce0b4f808d18ca8cea9')
sha256sums_x86_64=('8c0fb17e2ff71a682ec91f5f1c67f5b3dbc4347a5764a386486912077a3e2723')

source_x86_64=("${pkgname}_${pkgver}_x86_64.zip::https://github.com/sst/opencode/releases/download/v${pkgver}/opencode-linux-x64.zip")

package() {
  install -Dm755 ./opencode "${pkgdir}/usr/bin/opencode"
}