fix(ci): release failures for grocy and speedtest-tracker on Ubuntu 26.04 base

[Copilot]

The renovate-bumped base image was rebuilt on Ubuntu 26.04 ("resolute"), breaking both apps: ppa:ondrej/php has no resolute release, and the base now ships PHP 8.5 (no php8.3-* packages).

apps/grocy/Dockerfile

• Drop the now-404 add-apt-repository ppa:ondrej/php and the matching software-properties-common / gnupg2 install+purge.
• Install php8.5-* directly from the base image's repos.

apps/speedtest-tracker/Dockerfile

• Bump php8.3-* → php8.5-* (packages and /etc/php/8.5/... config paths).
• Add php8.5-curl and php8.5-zip — composer requires ext-curl/ext-zip, previously satisfied transitively by the 8.3 metapackages.
• Fix Ookla speedtest-cli download: the CDN now 403s on linux-amd64/linux-arm64; map TARGETARCH to canonical x86_64/aarch64.
• Switch the speedtest-cli curl calls to -fsSL / -fL so HTTP errors fail the build instead of silently producing a broken tarball.

case "$TARGETARCH" in amd64) CLI_ARCH=x86_64 ;; arm64) CLI_ARCH=aarch64 ;; *) CLI_ARCH="$TARGETARCH" ;; esac && \
curl -fL -o /tmp/speedtest-cli.tgz \
  "https://install.speedtest.net/app/cli/ookla-speedtest-${CLI_VERSION}-linux-${CLI_ARCH}.tgz"

Note

Bundled in one PR due to environment constraints; matches the source issue's combined scope. No docker-bake.hcl version changes — fixes are Dockerfile-only.