Properly set KRATOS_URL, add Hydra settings

Closes #1116

See merge request stackspin/stackspin!771

Resolve "Use helmRepository instead of gitRepository for Zulip"

Closes #1096

See merge request stackspin/stackspin!764

Update Helm release single-sign-on to v0.7.6

See merge request stackspin/stackspin!772

Update Helm release postgresql to v10.16.2

See merge request stackspin/stackspin!769

Update dependency pyparsing to v3.0.7

See merge request stackspin/stackspin!770

Resolve "Remove persistent volume for zulip's redis"

Closes #1070

See merge request stackspin/stackspin!762

add gitleaks to pre-commit hook to make sure secrets are not added

See merge request stackspin/stackspin!741

Improve installation documentation, make SMTP settings mandatory

Closes #623 and #1054

See merge request stackspin/stackspin!751

Update Helm release single-sign-on to v0.7.5

See merge request stackspin/stackspin!766

Update dependency dnspython to v2.2.0

See merge request stackspin/stackspin!765

Resolve "Add new callback URL for Hydra"

Closes #1114

See merge request stackspin/stackspin!763

Update dependency sphinx to v4.4.0

See merge request stackspin/stackspin!758

Update Helm release metallb to v2.6.1

See merge request stackspin/stackspin!759

Update Helm release ingress-nginx to v4.0.16

See merge request stackspin/stackspin!761

Update SSO to version 0.7.4

See merge request stackspin/stackspin!755

Update k3s to a version that supports 1.23

Closes #1076 and #1113

See merge request stackspin/stackspin!760