Rename ACE and IEA timeseries regions to the publications' names.

depends on #968

ACE: rename "South East Asia" to "ASEAN" in the four *-2024_timeseries.json files, in the geography.regions key of the ACE metadata, and in its keyFeatures and dataAvailability entries.
IEA: rename the APS and STEPS timeseries from "South East Asia" to "Southeast Asia". This also fixes the IEA "data in tool" badge, which is outlined today because the two spellings differ.
Then run build:timeseries.

Done in #974, merged into epic/v2; this closes when #937 reaches main.

ACE: the four timeseries now say ASEAN. ACE's metadata (regions, keyFeatures, dataAvailability) already said ASEAN throughout.
IEA: the APS and STEPS timeseries now say Southeast Asia.
The index was rebuilt, so IEA's "data in tool" badge now shows as filled. The spelling workarounds were then removed in refactor: drop the geography spelling folds #945 needed #980 (Data: IEA pathways spell the same region two ways across metadata and timeseries #945).

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