Add logic to skip project wikis

requested review from @cguindon, @epoirier, @fgurr, and @zhoufang

mentioned in issue eclipsefdn/helpdesk#1180 (closed)

approved this merge request

resolved all threads

approved this merge request

Test results:

❯ git push origin HEAD -uf
Enumerating objects: 4, done.
Counting objects: 100% (4/4), done.
Delta compression using up to 8 threads
Compressing objects: 100% (2/2), done.
Writing objects: 100% (3/3), 276 bytes | 276.00 KiB/s, done.
Total 3 (delta 0), reused 0 (delta 0), pack-reused 0
remote: Non-Eclipse project repository detected: ECA validation will be skipped.
remote: 
remote: Note that any issues with sign off or committer access will be flagged upon merging into the main project repository.
remote: 
remote: ========================================================================
remote: 
remote:       THIS IS ONLY A TEST INSTANCE. DON'T DO IMPORTANT WORK HERE!
remote: 
remote: ========================================================================
remote: 
remote: 
remote: To create a merge request for malowe/1, visit:
remote:   https://gitlab-test.eclipse.org/malowe/dash-gitlab-testing/-/merge_requests/new?merge_request%5Bsource_branch%5D=malowe%2F1
remote: 
To gitlab-test.eclipse.org:malowe/dash-gitlab-testing.git
 + 0e78c3f...3af0c69 HEAD -> malowe/1 (forced update)
branch 'malowe/1' set up to track 'origin/malowe/1'.
❯ cd ..
❯ git clone git@gitlab-test.eclipse.org:malowe/dash-gitlab-testing.wiki.git
Cloning into 'dash-gitlab-testing.wiki'...
warning: You appear to have cloned an empty repository.
❯ cd dash-gitlab-testing.wiki
❯ touch README.md
❯ git add .
❯ git commit -m "Test"
[master (root-commit) 2f8dff8] Test
 1 file changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 README.md
❯ git push
Enumerating objects: 3, done.
Counting objects: 100% (3/3), done.
Writing objects: 100% (3/3), 220 bytes | 220.00 KiB/s, done.
Total 3 (delta 0), reused 0 (delta 0), pack-reused 0
remote: Repository is a project wiki and not bound by ECA, skipping
remote: 
remote: ========================================================================
remote: 
remote:       THIS IS ONLY A TEST INSTANCE. DON'T DO IMPORTANT WORK HERE!
remote: 
remote: ========================================================================
remote: 
To gitlab-test.eclipse.org:malowe/dash-gitlab-testing.wiki.git
 * [new branch]      master -> master

merged

mentioned in commit 78901c7c