Fix LegacyKeyValueFormat report from docker build

[homersimpsons]

Merge split (requested in #152305 (comment)):

1. aarch64-gnu-debug (1): Fix LegacyKeyValueFormat report from docker build: aarch64-gnu-debug #153109
2. aarch64 (3): Fix LegacyKeyValueFormat report from docker build: host-aarch64 #153223
3. disabled/ (11): Fix LegacyKeyValueFormat report from docker build: disabled #153224
4. arm (7): Fix LegacyKeyValueFormat report from docker build: arm #153371
5. x86_64-gnu (10): Fix LegacyKeyValueFormat report from docker build: x86_64-gnu #153372
6. dist-x86_64 (6): Fix LegacyKeyValueFormat report from docker build: dist-x86_64 #153374
7. powerpc (5): Fix LegacyKeyValueFormat report from docker build: powerpc #153373
8. i686 (4): Fix LegacyKeyValueFormat report from docker build: i686 #153526
9. ohos (2): Fix LegacyKeyValueFormat report from docker build: ohos #153527
10. mips (4): Fix LegacyKeyValueFormat report from docker build: mips #153528
11. pr-check-1, pr-check-2, tidy (3): Fix LegacyKeyValueFormat report from docker build: pr #153529
12. dist-various-1, dist-various-2, test-various (3): Fix LegacyKeyValueFormat report from docker build: various #153531
13. dist-android, dist-loongarch64-linux, dist-loongarch64-musl, dist-riscv64-linux, dist-s390x-linux, dist-sparcv9-solaris, x86_64-fuchsia, x86_64-rust-for-linux (8): Fix LegacyKeyValueFormat report from docker build: miscellaneous #153533

While checking job logs (https://github.com/rust-lang/rust/actions/runs/21779827147/job/62842068357#step:28:217) I noticed:

 2 warnings found (use docker --debug to expand):
- LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format (line 24)
- LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format (line 29)

I identified warnings with:

git ls-files --directory **/Dockerfile | sed -E -e "s/(\/Dockerfile)//"|xargs --verbose --replace={} docker build --check {}

I went with ENV ENVVAR="quoted" because it is the most working solution I found. Note that I did not touch lines that did not report a warning but that were written as ENV ENVVAR=unquoted or ENV ENVVAR=multi \\n line.

FROM alpine
ENV INLINE_UNQUOTE=this is a test
ENV INLINE_QUOTE="this is a test"ENV MULTILINE_UNQUOTE= \
this \
is \
a \
test
ENV MULTILINE_QUOTE="\ this \ is \ a \ test"

[rustbot]

r? @marcoieni

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Why was this reviewer chosen?

The reviewer was selected based on:

• Owners of files modified in this PR: infra-ci
• infra-ci expanded to Kobzol, Mark-Simulacrum, jdno, jieyouxu, marcoieni
• Random selection from Mark-Simulacrum, jdno, jieyouxu, marcoieni

[homersimpsons]

Note that here docker reports:

WARNING: UndefinedVar - https://docs.docker.com/go/dockerfile/rule/undefined-var/
Usage of undefined variable '$CPATH' (did you mean $PATH?)
src/ci/docker/host-aarch64/dist-aarch64-linux/Dockerfile:77
--------------------
75 | ENV HOSTS=aarch64-unknown-linux-gnu
76 |
77 | >>> ENV CPATH=/usr/include/aarch64-linux-gnu/:$CPATH
78 |
79 | ENV RUST_CONFIGURE_ARGS=" \

I'm not sure if this warning should be fixed or if there is an error regarding this.

(That is the sole remaining warning after this commit)

[homersimpsons]

My IDE probably did that, should I revert?