chore(repo): fix typo

[Marcofann]

This pull request addresses a variety of typographical errors found in multiple files across the repository. The changes improve the readability, grammar, and accuracy of comments and documentation.

Files and Changes:

1. run-a-mainnet-taiko-node-from-source.mdx:

   • Fixed "a Ethereum node" to "an Ethereum node".

2. server.go (packages/guardian-prover-health-check/http/server.go and packages/relayer/pkg/http/server.go):

   • Corrected "an guardian" to "a guardian".
   • Corrected "an relayer" to "a relayer".

3. Bridge2_sendMessage.t.sol:

   • Fixed "an bridge" to "a bridge".

4. wait_header_synced.go:

   • Changed "a event" to "an event".

5. fixed_k_signer.go:

   • Updated "a ethereum" to "an ethereum".

6. helper.go:

   • Corrected "an valid" to "a valid".

7. dial.go:

   • Fixed "a ethereum" to "an ethereum".

8. DcapTestUtils.t.sol:

   • Fixed multiple instances of "an hexadecimal" to "a hexadecimal".

Notes to Reviewers:

• These changes are focused solely on grammatical corrections and do not introduce any functional changes to the code.
• Please ensure that no additional context or meaning was unintentionally altered during these edits.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 16.83%. Comparing base (d6001d3) to head (1fd2c82).
Report is 671 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main   #18667       +/-   ##
===========================================
- Coverage   49.37%   16.83%   -32.55%     
===========================================
  Files          56      107       +51     
  Lines        5827    23020    +17193     
===========================================
+ Hits         2877     3875      +998     
- Misses       2636    18733    +16097     
- Partials      314      412       +98     

Flag	Coverage Δ
guardian-prover-health-check	12.61% <ø> (?)

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[RogerLamTd]

We typically don't accept typo PRs, and this one spans across several packages. I'll include the changes in several PRs, thank you for the contribution.