docker compose: make GitHub/GitLab user and key effectively optional

> [!NOTE]
> Migrated from [augurlabs/augur#3633](https://github.com/augurlabs/augur/issues/3633)
> Originally opened by `@giordano` on 2026-01-29

---

**Is your feature request related to a problem? If so, please describe the problem:**

Follow up to https://github.com/chaoss/augur/pull/3300#pullrequestreview-3319439365, it should be possible to make the user and keys effectively optional.

**Potential solutions:**

Untested, but I'm mildly sure that something like
```diff
diff --git a/scripts/install/config.sh b/scripts/install/config.sh
index 0408b0aa0..6134c378d 100755
--- a/scripts/install/config.sh
+++ b/scripts/install/config.sh
@@ -15,6 +15,10 @@ function blank_confirm() {

confirm_placeholder=${!1}

+ if [ -t 0 ]; then
+ return
+ fi
+
while [ -z "${confirm_placeholder}" ]; do
echo "You entered a blank line, are you sure?"
read -p "enter 'yes' to continue, or enter the intended value: " confirm_placeholder
```
should do the trick.

**Additional context:**

This is a CHAOSS Con rapid prototyping experiment.