Force scio coders on all input SCollection

[RustedBones]

Some scio IOs were not seting scio coders on the underlying PCollection and relying on the default coder provided by beam. This can cause issues:

• coder options are not respected (Nullable)
• union may fail. Default beam coders are not 'wrapped'. The beam runtime check on coder equality fails.

[RustedBones]

Drop this as done in #4590. This coder can't be called on a generic type with bounds.

[codecov]

Codecov Report

Merging #4713 (bd0fd49) into main (1c30980) will decrease coverage by 0.02%.
The diff coverage is 30.95%.

❗ Current head bd0fd49 differs from pull request most recent head 841f023. Consider uploading reports for the commit 841f023 to get more accurate results

@@            Coverage Diff             @@
##             main    #4713      +/-   ##
==========================================
- Coverage   60.94%   60.93%   -0.02%     
==========================================
  Files         286      286              
  Lines       10467    10479      +12     
  Branches      750      755       +5     
==========================================
+ Hits         6379     6385       +6     
- Misses       4088     4094       +6     

Impacted Files	Coverage Δ
...n/scala/com/spotify/scio/bigquery/BigQueryIO.scala	39.13% <0.00%> (-0.50%)	⬇️
...n/scala/com/spotify/scio/bigtable/BigTableIO.scala	20.00% <0.00%> (-0.52%)	⬇️
...scala/com/spotify/scio/datastore/DatastoreIO.scala	16.66% <0.00%> (+4.16%)	⬆️
.../main/scala/com/spotify/scio/pubsub/PubsubIO.scala	9.87% <0.00%> (-0.52%)	⬇️
...ain/scala/com/spotify/scio/spanner/SpannerIO.scala	23.07% <0.00%> (-0.93%)	⬇️
.../src/main/scala/com/spotify/scio/jdbc/JdbcIO.scala	27.50% <0.00%> (ø)
.../spotify/scio/jdbc/sharded/JdbcShardedSelect.scala	16.66% <0.00%> (ø)
.../src/main/scala/com/spotify/scio/avro/AvroIO.scala	93.00% <100.00%> (+0.14%)	⬆️
...com/spotify/scio/coders/instances/AvroCoders.scala	82.35% <100.00%> (+2.35%)	⬆️
...re/src/main/scala/com/spotify/scio/io/TextIO.scala	100.00% <100.00%> (ø)
... and 5 more

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