GIT_CONFIG_KEY_ handling doesn't merge existing environment variables in #40580
Description
Describe the proposed change(s).
As noted in #40080 and #40575, we've seen reports that this has broken (at some point).
I've been able to reproduce this in https://github.com/JamieTanna-Mend-testing/issue-40575 after:
source .env
env LOG_FILE=debug.log LOG_LEVEL=debug npx renovate@42.85.2 --token $(gh auth token) JamieTanna-Mend-testing/$(basename $PWD)
It appears that process.env is set correctly, and we detect that the values are there, correctly index the newly added variables, but don't insert existing variables:
INFO: jvt (repository=JamieTanna-Mend-testing/issue-40575, branch=renovate/private-go-module-child-digest)
"env": {
"GIT_CONFIG_COUNT": "2",
"GIT_CONFIG_KEY_0": "url.https://**redacted**@github.com/.insteadOf",
"GIT_CONFIG_VALUE_0": "git@github.com:",
"GIT_CONFIG_KEY_1": "url.https://**redacted**@github.com/.insteadOf",
"GIT_CONFIG_VALUE_1": "https://github.com/",
"GIT_SSH_COMMAND": "ssh -o BatchMode=yes"
}
INFO: jvt (repository=JamieTanna-Mend-testing/issue-40575, branch=renovate/private-go-module-child-digest)
"gitSubmoduleAuthEnvironmentVariables": {
"GIT_CONFIG_KEY_2": "url.https://**redacted**@github.com/.insteadOf",
"GIT_CONFIG_VALUE_2": "ssh://**redacted**@github.com/",
"GIT_CONFIG_KEY_3": "url.https://**redacted**@github.com/.insteadOf",
"GIT_CONFIG_VALUE_3": "git@github.com:",
"GIT_CONFIG_KEY_4": "url.https://**redacted**@github.com/.insteadOf",
"GIT_CONFIG_VALUE_4": "https://github.com/",
"GIT_CONFIG_COUNT": "5"
},
"gitEnv": {
"HOME": "/Users/jamietanna",
"PATH": "...",
"LANG": "en_GB.UTF-8",
"GIT_CONFIG_KEY_2": "url.https://**redacted**@github.com/.insteadOf",
"GIT_CONFIG_VALUE_2": "ssh://**redacted**@github.com/",
"GIT_CONFIG_KEY_3": "url.https://**redacted**@github.com/.insteadOf",
"GIT_CONFIG_VALUE_3": "git@github.com:",
"GIT_CONFIG_KEY_4": "url.https://**redacted**@github.com/.insteadOf",
"GIT_CONFIG_VALUE_4": "https://github.com/",
"GIT_CONFIG_COUNT": "5"
}