bug#60589: guix build --keep-going (-k) not always honored

[Jonathan Brielmaier]

I can confirm this bug.

```
$ guix describe
  guix ea2fa86
    Repository-URL: https://git.savannah.gnu.org/git/guix.git
    Branch: master
    Commit: ea2fa86f31a83195ac789a6d92bcaee8e53e4397
```

My example involves a bit more packages. Those who got back by `guix
refresh --list-dependent icu4c`.

```
$ guix build --keep-going icecat-minimal@102.8.0-guix0-preview1
icedove-minimal@102.7.2 geierlein@0.9.13 icedove@102.7.2 mozjs@102.2.0
ungoogled-chromium-wayland@109.0.5414.119-1 r-metap@1.8 r-fmri@1.9.6
r-altmeta@4.1 r-puniform@0.2.5 r-untb@1.7-4 r-prospectr@0.2.6
js-mathjax@3.2.0 node-color-name@1.1.3 node-statsd-parser@0.0.4
node-stack-trace@0.0.10-1.4fd379e node-irc@0.5.2 node-env-variable@0.0.4
node-crx3@1.1.3 node-segfault-handler@1.3.0 node-sqlite3@5.0.2
node-serialport@9.2.7 node-mersenne@0.0.4 node-once@1.4.0
python-ikarus@0.0.2 python-pyside-6@6.3.1 tree-sitter-r@0.0.1-0.80efda5
tree-sitter-org@1.3.1-0.081179c tree-sitter-scheme@0.2.0-0.67b90a3
tree-sitter-bash@0.19.0 emacs-jsdoc@0.3 tree-sitter-elm@5.6.3
tree-sitter-go@0.19.1-0.64457ea tree-sitter-python@0.20.0-0.9e53981
tree-sitter-typescript@0.20.1 tree-sitter-php@0.19.0-0.f860e59
tree-sitter-clojure@0.0.11 tree-sitter-cpp@0.20.0-0.56cec4c
tree-sitter-julia@0.19.0 tree-sitter-rust@0.20.3 tree-sitter-html@0.19.0
tree-sitter-elixir@0.19.0-0.b20eaa7 tree-sitter-racket@0.1.0-0.1a5df02
tree-sitter-c-sharp@0.19.1 tree-sitter-java@0.20.0
tree-sitter-ocaml@0.20.1 tree-sitter-haskell@0.14.0-0.3bdba07
tree-sitter-markdown-gfm@0.7.1 tree-sitter-json@0.19.0
tree-sitter-ruby@0.19.0-0.206c707 tree-sitter-css@0.19.0
tree-sitter-markdown@0.1.1 laminar@1.2 r-bionero@1.6.0 r-zra@0.2
js-es5-shim@4.5.13 js-respond@1.4.2 js-html5shiv@3.7.3
js-json2@2016-10-28.1-031b1d9 mate@1.24.1 gr-satellites@4.6.0
gr-dsd@1.0.0-0.f9b9936 gnss-sdr@0.0.17 gqrx@2.15.9 urh@2.9.4
r-ggghost@0.2.1 r-asics@2.14.0 r-biosigner@1.26.0 r-alphabeta@1.12.0
r-btools@0.0.1-1.fa21d4c r-giotto@1.1.2-1.3c8067c r-chipseeker@1.34.1
r-ggalt@0.4.0 r-scone@1.22.0 r-copykat@1.0.8-0.256de33 r-ztpln@0.1.2
snap@7.0.5 r-barcodetrackr@1.6.0 r-rqc@1.32.0 r-gqtlstats@1.21.3
r-inspect@1.28.0 r-cicero-monocle3@1.3.2-1.fa2fb65 r-pore@0.24
r-tablerdash@0.1.0 r-battenberg@2.2.9 r-rnaseqdtu@2.0-1.5bee1e7
r-activpal@0.1.3 r-chemometricswithr@0.1.13 r-shinycustomloader@0.9.0
r-fresh@0.2.0 r-mlinterfaces@1.78.0 r-zscorer@0.3.1 r-abseqr@1.16.0
r-bigpint@1.14.0 r-actcd@1.2-0 r-shinyjqui@0.4.1 r-ggthemeassist@0.1.5
r-treemap@2.4-3 r-golem@0.3.5 r-learnr@0.11.2 r-ztable@0.2.3
r-hrbrthemes@0.8.0 r-abacus@1.0.0 r-citr@0.3.2 r-manipulatewidget@0.11.1
r-abstractr@0.1.0 r-shapforxgboost@0.1.1 r-shinyhelper@0.3.2
r-hierfstat@0.5-11 r-rmetasim@3.1.14 r-abtest@1.0.1
r-sankeyd3@0.3.2-1.fd50a74 r-infercnv@1.14.0
r-doubletcollection@1.1.0-1.c0d62f1 r-sccustomize@0.7.0-1.8414d1f
r-seuratwrappers@0.3.1-1.d28512f r-domultibarheatmap@0.1.0-1.9e65afa
r-seuratdisk@0.0.0.9019-1.163f1aa r-soupx@0.3.1-1.a3354be r-adapr@2.0.0
r-samr@3.0 r-biocpkgtools@1.16.0 r-fmcsr@1.40.0 r-bioassayr@1.36.0
r-alevinqc@1.14.0 r-maser@1.16.0 r-cistopic-next@0.3.0-1.04cecbb
r-anvil@1.10.1 r-cistopic@2.1.0 r-bionetstat@1.18.0 r-animalcules@1.14.0
r-aspli@2.8.0 r-icobra@1.26.0 r-atacseqqc@1.22.0
r-phastcons100way-ucsc-hg19@3.7.2 r-amaretto@1.13.0 r-bioconcotk@1.18.0
r-msnid@1.32.0 r-scannotatr@1.4.0 r-isoformswitchanalyzer@1.20.0
r-celldex@1.6.0 r-atena@1.4.0 r-adductomicsr@1.14.0 r-biscuiteer@1.12.0
r-circrnaprofiler@1.12.0 r-circus@0.1.7 r-rgreat@2.0.2
r-variantfiltering@1.34.0 r-archr@1.0.1-1.92ab814 rcas-web@0.1.0
r-adamgui@1.14.0 r-pcaexplorer@2.24.0 r-chromunity@0.0.1-1.09fce8b
pigx@0.0.3 pigx-sars-cov-2@0.0.8 r-aasea@1.1.0 r-spectre@0.5.5-1.f6648ab
r-radiant-data@1.5.1 r-pando@1.0.1 r-tidyposterior@1.0.0
r-shinymanager@1.0.410 r-zooimage@5.5.2 node-openzwave-shared@1.7.2
```