Deprecate the exporters in the "trace" and "metric" sub-directories

[MrAlias]

Changes

no new Go code is included in this change -- all exporter packages that are being deprecated have been copied to their new location.

• The go.opentelemetry.io/otel/exporters/metric/prometheus is deprecated in favor of go.opentelemetry.io/otel/exporters/prometheus.
• The go.opentelemetry.io/otel/exporters/trace/jaeger is deprecated in favor of go.opentelemetry.io/otel/exporters/jaeger.
• The go.opentelemetry.io/otel/exporters/trace/zipkin is deprecated in favor of go.opentelemetry.io/otel/exporters/zipkin.
• Fix the dependabot check that was returning a false-positive check for the /trace and /metric modules.
• Add dependabot entry for the /trace and /metric modules.

Background

All exporters used to be grouped in the metric or trace directory within the exporter directory. When we introduced metric support to the stdout and otlp exporters, which already supported tracing, they did not fit in either directory and were moved up one level. Now that the OTLP exporter is being split internally into trace and metric packages it has forced the question if the trace and metric directory within exporters makes sense.

It does not. It is an added hierarchical level to a package name that does not add useful context. Users of Prometheus know it is used for metrics and users of Jaeger and Zipkin know they are used for tracing.

This is a conclusion the rest of the OpenTelemetry SDKs have also realized. They have all included these exporters at the same directory level:

• https://github.com/open-telemetry/opentelemetry-java/tree/main/exporters
• https://github.com/open-telemetry/opentelemetry-python/tree/main/exporter
• https://github.com/open-telemetry/opentelemetry-js/tree/main/packages
• https://github.com/open-telemetry/opentelemetry-ruby/tree/main/exporter
• https://github.com/open-telemetry/opentelemetry-dotnet/tree/main/src
• https://github.com/open-telemetry/opentelemetry-cpp/tree/main/exporters
• https://github.com/open-telemetry/opentelemetry-php/tree/main/contrib
• https://github.com/open-telemetry/opentelemetry-rust

This change starts the removal of duplicate and unneeded hierarchical separation and unifies on a project structure closer matching the rest of the OpenTelemetry community. The deprecated package are planned to be removed for the 1.0.0 release.

[codecov]

Codecov Report

Merging #1993 (3053022) into main (377f7ce) will decrease coverage by 30.6%.
The diff coverage is 11.3%.

@@           Coverage Diff            @@
##            main   #1993      +/-   ##
========================================
- Coverage   72.1%   41.5%   -30.7%     
========================================
  Files        159     216      +57     
  Lines       7923   15668    +7745     
========================================
+ Hits        5719    6512     +793     
- Misses      1975    8760    +6785     
- Partials     229     396     +167     

Impacted Files	Coverage Δ
...internal/gen-go/agent/agent-remote/agent-remote.go	0.0% <0.0%> (ø)
...gen-go/jaeger/collector-remote/collector-remote.go	0.0% <0.0%> (ø)
exporters/jaeger/internal/gen-go/jaeger/jaeger.go	3.5% <ø> (ø)
...zipkin_collector-remote/zipkin_collector-remote.go	0.0% <0.0%> (ø)
...rs/jaeger/internal/gen-go/zipkincore/zipkincore.go	0.0% <0.0%> (ø)
...arty/thrift/lib/go/thrift/application_exception.go	0.0% <0.0%> (ø)
...hird_party/thrift/lib/go/thrift/binary_protocol.go	0.0% <0.0%> (ø)
...d_party/thrift/lib/go/thrift/buffered_transport.go	0.0% <0.0%> (ø)
.../third_party/thrift/lib/go/thrift/configuration.go	0.0% <0.0%> (ø)
...third_party/thrift/lib/go/thrift/debug_protocol.go	0.0% <0.0%> (ø)
... and 105 more

[MrAlias]

Markdown lint check is going to fail until this is merged into main.