Bump Go to 1.25 (#456)

<!-- Provide a brief summary of your changes -->

## Motivation and Context
<!-- Why is this change needed? What problem does it solve? -->
The following PR:
* Bumps Go to the latest stable version
* Moves away from setting the Go version as an env var in favour of
reading it automatically from the go.mod file (better consistency)

Closes: #447 

## How Has This Been Tested?
<!-- Have you tested this in a real application? Which scenarios were
tested? -->
Locally 

## Breaking Changes
<!-- Will users need to update their code or configurations? -->
No

## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] 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 change)
- [ ] Documentation update

## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [ ] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [ ] My code follows the repository's style guidelines
- [ ] New and existing tests pass locally
- [ ] I have added appropriate error handling
- [ ] I have added or updated documentation as needed

## Additional context
<!-- Add any other context, implementation notes, or design decisions
-->

---------

Signed-off-by: Radoslav Dimitrov <radoslav@stacklok.com>

.github/workflows/ci.yml

@@ -6,9 +6,6 @@ on:
   pull_request:
     branches: [ main ]
 
-env:
-  GO_VERSION: '1.24.x'
-
 jobs:
   # Build, Lint, and Validate
   build-lint-validate:
@@ -21,7 +18,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@44694675825211faa026b3c33043df3e48a5fa00 #v5
       with:
-        go-version: ${{ env.GO_VERSION }}
+        go-version-file: 'go.mod'
 
     - name: Cache Go modules
       uses: actions/cache@0400d5f644dc74513175e3cd8d07132dd4860809 #v4
@@ -65,7 +62,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@44694675825211faa026b3c33043df3e48a5fa00 #v5
       with:
-        go-version: ${{ env.GO_VERSION }}
+        go-version-file: 'go.mod'
 
     - name: Cache Go modules
       uses: actions/cache@0400d5f644dc74513175e3cd8d07132dd4860809 #v4

.github/workflows/deploy.yml

@@ -7,7 +7,6 @@ on:
 
 env:
   PULUMI_VERSION: "3.188.0"
-  GO_VERSION: "1.24.6"
 
 jobs:
   docker-push:
@@ -66,7 +65,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@44694675825211faa026b3c33043df3e48a5fa00 #v5
         with:
-          go-version: ${{ env.GO_VERSION }}
+          go-version-file: 'go.mod'
 
       - name: Setup Pulumi
         uses: pulumi/actions@cc7494be991dba0978f7ffafaf995b0449a0998e #v6
@@ -105,7 +104,7 @@ jobs:
       - name: Setup Go
         uses: actions/setup-go@44694675825211faa026b3c33043df3e48a5fa00 #v5
         with:
-          go-version: ${{ env.GO_VERSION }}
+          go-version-file: 'go.mod'
 
       - name: Setup Pulumi
         uses: pulumi/actions@cc7494be991dba0978f7ffafaf995b0449a0998e #v6

.github/workflows/release.yml

@@ -21,7 +21,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@44694675825211faa026b3c33043df3e48a5fa00 #v5
         with:
-          go-version: '1.24.x'
+          go-version-file: 'go.mod'
 
       - name: Install cosign
         uses: sigstore/cosign-installer@d58896d6a1865668819e1d91763c7751a165e159 #v3

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.24-alpine AS builder
+FROM golang:1.25-alpine AS builder
 WORKDIR /app
 
 # Copy go mod files first and download dependencies

go.mod

@@ -1,6 +1,6 @@
 module github.com/modelcontextprotocol/registry
 
-go 1.24.0
+go 1.25
 
 require (
 	github.com/caarlos0/env/v11 v11.3.1