acceptance: add Glamsterdam to the L1 fork matrix after op-geth decoupling

## Summary

Add Glamsterdam to the required `op-acceptance-tests` L1-fork matrix after the monorepo has completed the op-geth decoupling and uses upstream go-ethereum.

## Context

#21920 intentionally changes the required L1-fork matrix from Prague to Fusaka only. Adding Glamsterdam now would couple the matrix to temporary, unreleased Glamsterdam support in the op-geth fork.

Once #20257 is complete, the matrix can use upstream go-ethereum's Glamsterdam support without extending op-geth.

## Acceptance criteria

- Add `glamsterdam` alongside `fusaka` in the required acceptance-test L1-fork matrix.
- Run both the op-node/op-reth and kona-node/op-reth variants.
- Add the Glamsterdam variants to the required CI gate.
- Confirm the full acceptance suite passes under both Glamsterdam variants.

Blocked by #20257.