ci: default fetched sccache to v0.16.0 (latest)

Bump the SCCACHE_DL_VERSION default 0.15.0 -> 0.16.0 (released 2026-06-19, the current latest). The x86_64-unknown-linux-musl asset is confirmed published; the fetch stays fail-safe (a missing version just falls back to an uncached build) and the value is overridable per-job.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Claude-Session: https://claude.ai/code/session_01LjWiKSyNzqqpobSKYRiew5

Author: claude

.github/build.sh

@@ -24,9 +24,9 @@ fi
 #
 # SCCACHE_DL_VERSION is overridable per-job, so a container that crashes one sccache build can
 # try another without editing this script (the in-container panic that stalled phase 2 was on
-# v0.8.2; v0.15.0 is the current stable default). A wrong/unavailable version just fails the
-# `curl -f` and falls back to an uncached build, so bumping it can never red a build.
-SCCACHE_DL_VERSION="${SCCACHE_DL_VERSION:-0.15.0}"
+# v0.8.2; v0.16.0 is the latest release and the default). A wrong/unavailable version just fails
+# the `curl -f` and falls back to an uncached build, so bumping it can never red a build.
+SCCACHE_DL_VERSION="${SCCACHE_DL_VERSION:-0.16.0}"
 if [ "${USE_CACHE:-true}" = "true" ] && [ -n "${SCCACHE_WEBDAV_TOKEN:-}${SCCACHE_GHA_ENABLED:-}" ] \
    && ! command -v sccache >/dev/null 2>&1 \
    && [ "$(uname -s)" = "Linux" ] && [ "$(uname -m)" = "x86_64" ]; then

CLAUDE.md

@@ -226,7 +226,7 @@ build. The probe above now makes that a safe fallback.) Order, each adding the e
 Per-job recipe: add `env:` { `USE_CACHE`, `SCCACHE_WEBDAV_ENDPOINT`, `SCCACHE_WEBDAV_TOKEN` } and
 `DOCKCROSS_ARGS: "-e SCCACHE_WEBDAV_ENDPOINT -e SCCACHE_WEBDAV_TOKEN -e USE_CACHE"` — the
 dockcross wrapper only forwards host env it is explicitly told to via `-e`. The fetched sccache
-version is the `SCCACHE_DL_VERSION` knob in `build.sh` (default **0.15.0**; overridable per-job
+version is the `SCCACHE_DL_VERSION` knob in `build.sh` (default **0.16.0**; overridable per-job
 to try a different build against a container that crashed another). **Windows** (`build.bat` +
 MSVC) is separate and last: use `mozilla-actions/sccache-action` / sccache's MSVC support, not
 the `build.sh` musl fetch.