refactor(instrumentation-grpc): fix eslint warnings

[chancancode]

Which problem is this PR solving?

Fixes the following eslint warnings in the instrumentation-grpc package:

/home/runner/work/opentelemetry-js/opentelemetry-js/experimental/packages/opentelemetry-instrumentation-grpc/src/clientUtils.ts
  105:42  warning  Unexpected any. Specify a different type  @typescript-eslint/no-explicit-any

/home/runner/work/opentelemetry-js/opentelemetry-js/experimental/packages/opentelemetry-instrumentation-grpc/src/instrumentation.ts
  129:69  warning  Unexpected any. Specify a different type  @typescript-eslint/no-explicit-any
  134:69  warning  Unexpected any. Specify a different type  @typescript-eslint/no-explicit-any
  139:68  warning  Unexpected any. Specify a different type  @typescript-eslint/no-explicit-any
  144:68  warning  Unexpected any. Specify a different type  @typescript-eslint/no-explicit-any

/home/runner/work/opentelemetry-js/opentelemetry-js/experimental/packages/opentelemetry-instrumentation-grpc/src/serverUtils.ts
  112:23  warning  Don't use `Function` as a type  @typescript-eslint/ban-types
  152:23  warning  Don't use `Function` as a type  @typescript-eslint/ban-types
  207:31  warning  Don't use `Function` as a type  @typescript-eslint/ban-types
  211:31  warning  Don't use `Function` as a type  @typescript-eslint/ban-types

/home/runner/work/opentelemetry-js/opentelemetry-js/experimental/packages/opentelemetry-instrumentation-grpc/test/helper.ts
  83:11  warning  Don't use `Function` as a type  @typescript-eslint/ban-types

Ref #5365

Short description of the changes

This commit does not involve any changes to runtime code and can be safely merged without any concerns about changing behavior.

The first can be replaced with the more precise type that we are expecting.

The second just wansn't needed anymore.

The third is highly unusual. After spending significant amount of time reading and stepping through the code – I am quite confident that the .call({}, ...) (and .apply({}, ...) elsewhere in the tests) are a mistake that we inherited from very old code. However I don't feel confident enough that I can explain what is going on here to make a change to the runtime code, so in the meantime, I think the best course of action is to leave it as-is, document the issue and have someone with more expertise untangle this down the road.

The last one was a change in test code to use a more precise call signature.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• eslint

Checklist:

• Followed the style guidelines of this project
• Unit tests have been added
• Documentation has been updated

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.64%. Comparing base (29d0da5) to head (ffae1a2).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #5408   +/-   ##
=======================================
  Coverage   94.64%   94.64%           
=======================================
  Files         318      318           
  Lines        8033     8033           
  Branches     1688     1688           
=======================================
  Hits         7603     7603           
  Misses        430      430           

Files with missing lines	Coverage Δ
...ntelemetry-instrumentation-grpc/src/clientUtils.ts	96.77% <100.00%> (ø)
...emetry-instrumentation-grpc/src/instrumentation.ts	96.25% <ø> (ø)
...ntelemetry-instrumentation-grpc/src/serverUtils.ts	90.66% <ø> (ø)