[block-executor] Remove unused executable type

[georgemitenkov]

Description

X: Executable is not used on block executor:

• It was not integrated into V1 loader.
• V2 loader ended up using a separate path for execution and concrete types (for now).
  Removing the type parameter from the executor, as wall as the old cross-block module cache implementation (we have a cache manager now). Old modules MVHashMap is still kept generic though.

How Has This Been Tested?

N/A

Key Areas to Review

N/A

Type of Change

• Refactoring

Which Components or Systems Does This Change Impact?

• Move/Aptos Virtual Machine

Checklist

• I have read and followed the CONTRIBUTING doc
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I identified and added all stakeholders and component owners affected by this change as reviewers
• I tested both happy and unhappy path of the functionality
• I have made corresponding changes to the documentation

[trunk-io]

⏱️ 16m total CI duration on this PR

Job	Cumulative Duration	Recent Runs
rust-move-tests	13m	🟩
rust-cargo-deny	2m	🟩
check-dynamic-deps	40s	🟩
general-lints	29s	🟩
semgrep/ci	27s	🟩
file_change_determinator	15s	🟩
permission-check	2s	🟩
permission-check	2s	🟩
check-branch-prefix	1s	🟩

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[georgemitenkov]

• [block-executor] Remove unused executable type #15601 👈 (View in Graphite)
• main

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