[Bug]: deltaproxy ignores proxy_merge_pillar_in_opts, and drops a proxymodule module_executors declaration for sub-proxies

Description

Two places where deltaproxy's proxy setup diverges from the single-proxy metaproxy.

1. The control proxy's pillar is merged into opts unconditionally, ignoring proxy_merge_pillar_in_opts.

salt/metaproxy/proxy.py guards the merge:

if self.opts.get("proxy_merge_pillar_in_opts"):
    # Override proxy opts with pillar data when the user required. But do
    # not override master in opts.
    pillar = copy.deepcopy(self.opts["pillar"])
    ...
elif self.opts.get("proxy_mines_pillar"):

salt/metaproxy/deltaproxy.py has no guard -- it always merges, then evaluates proxy_mines_pillar as a separate if. So the documented option (default False) has no effect and the control proxy's pillar always overrides its opts.

This does not stop at the control proxy. Sub-proxy opts begin as a copy of the control proxy's opts (proxyopts = opts.copy() in subproxy_post_master_init), so anything the control proxy's pillar injected into opts is inherited by every sub-proxy.

2. A proxymodule's module_executors declaration is ignored for sub-proxies.

post_master_init reads it for the control proxy:

self.module_executors = self.proxy.get(
    f"{fq_proxyname}.module_executors", lambda: []
)()

subproxy_post_master_init never sets it, so when thread_return does getattr(minion_instance, "module_executors", []) the attribute is missing and it falls through to the opts default. The single-proxy metaproxy honours the declaration.

Setup

salt 3008.2, one control proxy dpcontrol with three sub-proxies using the dummy proxytype.

Steps to reproduce -- 1

Put a plain key in the control proxy's pillar and leave proxy_merge_pillar_in_opts unset:

# control proxy pillar
proxy:
  proxytype: deltaproxy
  ids: [minion1, minion2, minion3]
n_marker: LEAKED_FROM_PILLAR

Then read it back from opts only:

salt dpcontrol config.get n_marker omit_pillar=True
salt minion1   config.get n_marker omit_pillar=True
salt minion2   config.get n_marker omit_pillar=True

Observed: all three return LEAKED_FROM_PILLAR, so the pillar key became an opts key on the control proxy and on every sub-proxy.
Expected: empty, since proxy_merge_pillar_in_opts is not set. With it set to True the merge should happen, as it does for a single proxy.

Steps to reproduce -- 2

Give the proxymodule a module_executors function:

def module_executors():
    return ["direct_call"]

Instrumenting thread_return to report what it resolved shows the attribute is absent on every sub-proxy:

id=minion1 has_attr=False value='<MISSING>'
id=minion2 has_attr=False value='<MISSING>'
id=minion3 has_attr=False value='<MISSING>'

Expected: the sub-proxies pick up the proxymodule's declaration, as the control proxy and the single-proxy metaproxy do.

Versions Report

Salt Version:
           Salt: 3008.2
Python Version:
         Python: 3.10
Salt Package Information:
   Package Type: onedir

Both reproduce against the current 3008.x branch head.

Compare salt/metaproxy/deltaproxy.py with salt/metaproxy/proxy.py, starting at subproxy_post_master_init, post_master_init, and thread_return. Verify the relevant deltaproxy tests or reproduction setup, then confirm that proxy_merge_pillar_in_opts controls the merge and that sub-proxies honor the proxymodule's module_executors declaration.