Fix version extraction regex to exclude trailing quote

Corrects regex pattern in build-testharness.yml to match the pattern
used in build-authenticator.yml. The previous regex captured the
closing quote as part of the version name, which would result in
malformed version strings.

Before: regex='appVersionName = "([^"]+")'  → captures "2025.11.1"
After:  regex='appVersionName = "([^"]+)"'  → captures "2025.11.1"

Addresses Finding 2 from code review of PR #6181.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: SaintPatrck

.github/workflows/build-testharness.yml

@@ -101,7 +101,7 @@ jobs:
           versionCode:"$VERSION_CODE" \
           versionName:"$VERSION_NAME_INPUT"
 
-          regex='appVersionName = "([^"]+")'
+          regex='appVersionName = "([^"]+)"'
           if [[ "$(cat gradle/libs.versions.toml)" =~ $regex ]]; then
             VERSION_NAME="${BASH_REMATCH[1]}"
           fi