Fix: Remove tool installation from Go Tip workflow (jaegertracing#7716)

## Which problem is this PR solving?
-  Resolves jaegertracing#7664
## Description of the changes
- Removed the installation of stable Go and test dependencies (make
install-test-tools) from the
ci-unit-tests-go-tip.yml
 workflow.
- Removed the "Lint" step, which was previously a placeholder and not
performing actual linting in this workflow.
- This ensures that tools (like linters) are not built using the
potentially unstable Go Tip version, preventing unrelated build failures
during Go Tip testing. The workflow now strictly focuses on compiling
and running unit tests for Jaeger's core code against Go Tip.

## How was this change tested?
- Tested by verifying that the workflow configuration is valid and
correctly invokes make test-ci without the unnecessary prerequisite
steps.
- The change purely modifies the CI configuration to align with the
requirement of not testing tools against Go Tip.

---------

Signed-off-by: Chinmay Mehrotra <[email protected]>
Signed-off-by: Mend Renovate <[email protected]>
Signed-off-by: Yuri Shkuro <[email protected]>
Co-authored-by: Chinmay Mehrotra <[email protected]>
Co-authored-by: Mend Renovate <[email protected]>
Co-authored-by: Mahad Zaryab <[email protected]>
Co-authored-by: Yuri Shkuro <[email protected]>

Author: 5 people

.github/workflows/ci-unit-tests-go-tip.yml

@@ -26,15 +26,6 @@ jobs:
 
     - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
 
-    - name: Set up stable Go for tools
-      uses: actions/setup-go@4dc6199c7b1a012772edbd06daecab0f50c9053c # v6.1.0
-      with:
-        go-version: 1.25.x
-
-    - name: Install test deps
-      # even though the same target runs from test-ci, running it separately makes for cleaner log in GH workflow
-      run: make install-test-tools
-
     - name: Install Go Tip
       uses: ./.github/actions/setup-go-tip
       with:
@@ -48,5 +39,4 @@ jobs:
     - name: Run unit tests
       run: make test-ci
 
-    - name: Lint
-      run: echo skip linting on Go tip
+