refactor(ci): skip bincraft reinstall when image already has it (#72)

## Summary

bincraft is baked into the build-env images, but every workflow still unconditionally calls `pak::pak("git::.../bincraft.git")` (~30–60s per job).

Pin bincraft to a specific tag (currently `v4.0.2`) and guard the install on a version check.

```
- /opt/R/$R_VERSION/bin/R -q -e 'if (!requireNamespace("bincraft", quietly = TRUE) || packageVersion("bincraft") != "4.0.2") pak::pak("git::https://codefloe.com/rpkgs/bincraft.git@v4.0.2")'
```

- Image matches the pin → skip install entirely.
- Image is missing bincraft or has a different version → install the pinned tag (covers both broken bakes and intentional version bumps).
- Renovate customManager keeps the pin and the version-check string in sync whenever bincraft cuts a new tag (uses `git-tags` datasource against the bincraft repo).

Touches 43 `.crow` YAMLs + `renovate.json`.

Reviewed-on: #72

.crow/process-updates-redhat-8-arm64.yaml

@@ -51,7 +51,7 @@ steps:
     commands:
       - git clone -q https://pat-s:$$REPO_RO_TOKEN@git.devxy.io/devxy/build-cran-binaries.git .
       - rm -rf /mnt/cache/R-pkgs/00LOCK-r-pkg-binaries /mnt/cache/R-pkgs/00LOCK-bincraft /mnt/cache/R-pkgs/00LOCK-pak /mnt/cache/pkgcache/R/pkgcache /mnt/cache/pkgcache/R/pkgcache /mnt/cache/R-pkgs/pkgcache /mnt/cache/R-pkgs/00LOCK-pak/mnt/cache/R-pkgs/00LOCK-RPostgres /mnt/cache/R-pkgs/bincraft
-      - /opt/R/$R_VERSION/bin/R -q -e 'pak::pak("git::https://codefloe.com/rpkgs/bincraft.git")'
+      - /opt/R/$R_VERSION/bin/R -q -e 'if (!requireNamespace("bincraft", quietly = TRUE) || packageVersion("bincraft") != "4.1.0") pak::pak("git::https://codefloe.com/rpkgs/bincraft.git@v4.1.0")'
       - /opt/R/$R_VERSION/bin/R -q -e 'packageVersion("bincraft")'
       - mkdir -p /mnt/cache/pkgcache /mnt/cache/R-pkgs /mnt/cache/ccache /mnt/cache/packages
       # options(future.globals.onReference = NULL): for some reason s3fs::file_delete() throws 'Error: Detected a non-exportable reference ('externalptr') in one of the globals ('FUN' of class 'function') used in the future expression' otherwise