pgsql: Revert: Let table AM insertion methods control index insertion

Revert: Let table AM insertion methods control index insertion

This commit reverts b1484a3f19 per review by Andres Freund.

Discussion: https://postgr.es/m/20240410165236.rwyrny7ihi4ddxw4%40awork3.anarazel.de

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/da841aa4dc279bb0053de56121c927ec943edff3

Modified Files
--------------
src/backend/access/heap/heapam.c         |  4 +---
src/backend/access/heap/heapam_handler.c |  4 +---
src/backend/access/table/tableam.c       |  6 ++----
src/backend/catalog/indexing.c           |  4 +---
src/backend/commands/copyfrom.c          | 13 ++++---------
src/backend/commands/createas.c          |  4 +---
src/backend/commands/matview.c           |  4 +---
src/backend/commands/tablecmds.c         | 22 +++++-----------------
src/backend/executor/execReplication.c   |  6 ++----
src/backend/executor/nodeModifyTable.c   |  6 ++----
src/include/access/heapam.h              |  2 +-
src/include/access/tableam.h             | 25 +++++++------------------
12 files changed, 28 insertions(+), 72 deletions(-)