Do not publish docker release images on `-dev` tags (#25471)

Try to prevent what happened with tag `v1.21.0-dev` as outlined in
#25193.
Unfortunately, we cannot really test if it works as intended as we would
need to release a new `dev` tag for that.
Fixes #25193 (or at least attempts to).

---------

Co-authored-by: jolheiser <john.olheiser@gmail.com>

docker/manifest.rootless.tmpl

@@ -1,12 +1,14 @@
 image: gitea/gitea:{{#if build.tag}}{{trimPrefix "v" build.tag}}{{else}}{{#if (hasPrefix "refs/heads/release/v" build.ref)}}{{trimPrefix "refs/heads/release/v" build.ref}}-{{/if}}nightly{{/if}}-rootless
 {{#if build.tags}}
 {{#unless (contains "-rc" build.tag)}}
+{{#unless (contains "-dev" build.tag)}}
 tags:
 {{#each build.tags}}
   - {{this}}-rootless
 {{/each}}
   - "latest-rootless"
 {{/unless}}
+{{/unless}}
 {{/if}}
 manifests:
   -

docker/manifest.tmpl

@@ -1,12 +1,14 @@
 image: gitea/gitea:{{#if build.tag}}{{trimPrefix "v" build.tag}}{{else}}{{#if (hasPrefix "refs/heads/release/v" build.ref)}}{{trimPrefix "refs/heads/release/v" build.ref}}-{{/if}}nightly{{/if}}
 {{#if build.tags}}
 {{#unless (contains "-rc" build.tag)}}
+{{#unless (contains "-dev" build.tag)}}
 tags:
 {{#each build.tags}}
   - {{this}}
 {{/each}}
   - "latest"
 {{/unless}}
+{{/unless}}
 {{/if}}
 manifests:
   -