Fix nginx start and tweak CI

[thresheek]

Proposed changes

This PR fixes nginx binary startup as seen on the current image:

server  | >>> Starting nginx server...
server  | /usr/sbin/nginx: error while loading shared libraries: libpcre.so.3: cannot open shared object file: No such file or directory
server  | >>> Parameters:
server  | >>> Test case: handshake
server  | /usr/sbin/nginx: error while loading shared libraries: libpcre.so.3: cannot open shared object file: No such file or directory
server exited with code 127

Additionally, it adds a change to CI to trigger image rebuilds on workflow_dispatch events even if the commit id on the main nginx repo is the same as the currently built image.

[Copilot]

Pull Request Overview

This PR fixes nginx startup issues by updating the Docker build to use the correct PCRE library version and enhances CI to allow manual image rebuilds even when the nginx commit hasn't changed.

• Replaces deprecated libpcre3 packages with libpcre2-dev to resolve nginx binary startup errors
• Adds workflow_dispatch trigger support to force CI builds regardless of commit ID comparison

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
Dockerfile	Updates PCRE library from libpcre3 to libpcre2-dev to fix nginx startup dependency issues
.github/workflows/docker-publish.yml	Adds logic to trigger builds on manual workflow dispatch events

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[thresheek]

Even with the image built with that fix, I'm still getting errors in interop tests as documented in #14 (comment) - not sure what could cause that.

[thresheek]

I'm fairly sure the issue is in my environment somehow as the older image that was pasing the tests a couple days back on the online interop also exhibits the same issue.