Upgrade Go to 1.24.3 (#31220)

* Upgrade Go to 1.24.3

Updates the following files:
- server/.go-version: 1.23.9 → 1.24.3
- server/build/Dockerfile.buildenv: golang:1.23.9-bullseye → golang:1.24.3-bullseye
- server/go.mod: go 1.23.0 → go 1.24.3, toolchain go1.23.9 → go1.24.3
- server/public/go.mod: go 1.23.0 → go 1.24.3, toolchain go1.23.9 → go1.24.3

Also fixes non-constant format string errors introduced by Go 1.24.3's stricter format string checking:
- Added response() helper function in slashcommands/util.go for simple string responses
- Removed unused responsef() function from slashcommands/util.go
- Replaced responsef() with response() for translated strings that don't need formatting
- Fixed fmt.Errorf and fmt.Fprintf calls to use proper format verbs instead of string concatenation
- Updated marketplace buildURL to handle format strings conditionally

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Update generated mocks for Go 1.24.3

Regenerated mocks using mockery v2.53.4 to ensure compatibility with Go 1.24.3.
This addresses mock generation failures that occurred with the Go upgrade.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Update to bookworm and fix non-existent sha

Signed-off-by: Stavros Foteinopoulos <stafot@gmail.com>

* fix non-constant format string

---------

Signed-off-by: Stavros Foteinopoulos <stafot@gmail.com>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Stavros Foteinopoulos <stafot@gmail.com>

server/platform/shared/filestore/mocks/FileBackend.go

@@ -1,4 +1,4 @@
-// Code generated by mockery v2.42.2. DO NOT EDIT.
+// Code generated by mockery v2.53.4. DO NOT EDIT.
 
 // Regenerate this file using `make filestore-mocks`.
 
@@ -65,7 +65,7 @@ func (_m *FileBackend) CopyFile(oldPath string, newPath string) error {
 	return r0
 }
 
-// DriverName provides a mock function with given fields:
+// DriverName provides a mock function with no fields
 func (_m *FileBackend) DriverName() string {
 	ret := _m.Called()
 
@@ -341,7 +341,7 @@ func (_m *FileBackend) RemoveFile(path string) error {
 	return r0
 }
 
-// TestConnection provides a mock function with given fields:
+// TestConnection provides a mock function with no fields
 func (_m *FileBackend) TestConnection() error {
 	ret := _m.Called()
 

server/platform/shared/filestore/mocks/FileBackendWithLinkGenerator.go

@@ -1,4 +1,4 @@
-// Code generated by mockery v2.42.2. DO NOT EDIT.
+// Code generated by mockery v2.53.4. DO NOT EDIT.
 
 // Regenerate this file using `make filestore-mocks`.
 

server/platform/shared/filestore/mocks/ReadCloseSeeker.go

@@ -1,4 +1,4 @@
-// Code generated by mockery v2.42.2. DO NOT EDIT.
+// Code generated by mockery v2.53.4. DO NOT EDIT.
 
 // Regenerate this file using `make filestore-mocks`.
 
@@ -11,7 +11,7 @@ type ReadCloseSeeker struct {
 	mock.Mock
 }
 
-// Close provides a mock function with given fields:
+// Close provides a mock function with no fields
 func (_m *ReadCloseSeeker) Close() error {
 	ret := _m.Called()