refactor(tests): remove dead static-filler infrastructure

[leolara]

🗒️ Description

⏳ Draft — do not merge until #2556 is complete. Some of the pieces removed here may still be
needed to finish that work; see Related Issues.

tests/static/ (the legacy ethereum/tests-style YAML/JSON fillers) was removed after its
~1,900 fillers were hand-ported to Python tests under tests/ported_static/. Once porting and the
ethereum/tests archival parity check are complete, the entire static-filler stack is dead code
and is removed here — ~6,150 LOC net.

Three layers removed:

1. Fill path — the static_filler.py pytest plugin and the --fill-static-tests flag with
   all its plumbing: the conditional plugin loader and FixtureCollector.fill_static_tests field,
   and the unconditional -p …static_filler registration in pytest-fill.ini (this was loaded
   on every fill). No *Filler.{json,yml,yaml} files exist in the repo, so this path had no inputs.
2. Parser — specs/base_static.py and the entire specs/static_state/ package (the pydantic
   model tree that parsed legacy fillers).
3. Migration tools — scripts/filler_to_python/ (the filler→Python converter),
   cli/fillerconvert/, and cli/modify_static_test_gas_limits.py, plus their [project.scripts]
   entry points and scripts/verify_dynamic_addresses.sh.

Relocation (the one runtime link): 339 ported tests import resolve_expect_post /
resolve_expect_post_fork — runtime helpers that resolve expected post-state for a given
(d, g, v) and fork. These, plus their ForkSet/ForkConstraint/CMP/_match_index closure,
are moved out of the deleted parser into a new self-contained module
specs/post_state_resolution.py, and the 339 imports are codemod'd to the new path.

Also removed: the now-dead yul_test and compile_yul_with(fork) markers — the yul fixture
they keyed off lived only in static_filler.py, no test uses it, and they were never used for
selection.

⚠️ Breaking (public API): execution_testing.specs.BaseStaticTest and
execution_testing.specs.StateStaticTest are no longer exported. No in-repo consumers, but
downstream importers would need to drop them.

Kept on purpose: the ported_tests.py plugin and @ported_from markers (coverage tracking),
the solc.py plugin (used by tools/tests/test_code.py), and the general-purpose
Yul/Solc/YulCompiler helpers in tools_code.

Verification: just static passes; fill --collect-only collects the full suite cleanly
(confirming pytest-fill.ini loads without static_filler); a targeted fill exercising both
relocated functions (incl. the sole resolve_expect_post_fork user) passes; framework unit tests pass.

🔗 Related Issues or PRs

Sequenced after #2556 (archiving ethereum/tests). Some of the pieces removed here — in particular
the migration / parity tooling (scripts/filler_to_python, cli/fillerconvert) — may still be
needed to complete that work, as they are the in-repo oracle for verifying the archived fixtures are
a superset of the last ethereum/tests release. This PR should therefore be merged only after
#2556 is done.

✅ Checklist

• All: Ran fast static checks to avoid unnecessary CI fails (just static) — passes.
• All: PR title adheres to the repo standard — starts type(scope):.
• All: Considered updating the online docs in the ./docs/ directory — no docs/ references to the removed flag/parser; the only doc mention (.claude/commands/fill-tests.md) was updated.
• All: Set appropriate labels for the changes (only maintainers can apply labels).
• Tests: Ran mkdocs serve locally and verified the auto-generated docs for new tests — N/A (no new test cases; only an import-path codemod of existing tests).
• Tests: For PRs implementing a missed test case, update the post-mortem document — N/A (not a missed-test-case PR).
• Ported Tests: All converted JSON/YML tests have been assigned @ported_from marker — N/A (no newly converted tests; existing markers unchanged).

Cute Animal Picture

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.50%. Comparing base (14eca5d) to head (8ef92b4).
⚠️ Report is 1 commits behind head on forks/amsterdam.

Additional details and impacted files

@@               Coverage Diff                @@
##           forks/amsterdam    #2950   +/-   ##
================================================
  Coverage            90.50%   90.50%           
================================================
  Files                  535      535           
  Lines                32407    32407           
  Branches              3011     3011           
================================================
  Hits                 29331    29331           
  Misses                2559     2559           
  Partials               517      517           

Flag	Coverage Δ
unittests	90.50% <ø> (ø)

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