chore: replace http.NewRequest with http.NewRequestWithContext

Ensure proper context propagation for cancellation and timeout
support in all HTTP requests. The codebase already uses
NewRequestWithContext in 30+ places — these are the remaining
inconsistencies.

Fixes #7087

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: spboyer

cli/azd/extensions/azure.ai.agents/internal/project/parser.go

@@ -1038,7 +1038,7 @@ func registerAgent(uri, token, resourceID, ingressSuffix string) string {
 		}
 
 		client := &http.Client{}
-		req, err := http.NewRequest("POST", uri, bytes.NewBuffer(payloadBytes))
+		req, err := http.NewRequestWithContext(context.Background(), "POST", uri, bytes.NewBuffer(payloadBytes))
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "Error creating request: %v\n", err)
 			continue
@@ -1103,7 +1103,7 @@ func testUnauthenticatedAccess(acaEndpoint string) {
 	fmt.Printf("Request Body: %s\n", string(payload))
 
 	client := &http.Client{}
-	req, err := http.NewRequest("POST", uri, bytes.NewBuffer(payload))
+	req, err := http.NewRequestWithContext(context.Background(), "POST", uri, bytes.NewBuffer(payload))
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "Error creating request: %v\n", err)
 		return
@@ -1158,7 +1158,7 @@ func testDataPlane(endpoint, token, agentName, agentVersion string) {
 	fmt.Println(string(payloadBytes))
 
 	client := &http.Client{}
-	req, err := http.NewRequest("POST", uri, bytes.NewBuffer(payloadBytes))
+	req, err := http.NewRequestWithContext(context.Background(), "POST", uri, bytes.NewBuffer(payloadBytes))
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "Error creating request: %v\n", err)
 		return

cli/azd/internal/telemetry/appinsights-exporter/transmitter.go

@@ -8,6 +8,7 @@ package appinsightsexporter
 import (
 	"bytes"
 	"compress/gzip"
+	"context"
 	"encoding/json"
 	"io"
 	"net/http"
@@ -77,7 +78,7 @@ func (transmitter *httpTransmitter) Transmit(payload []byte, items TelemetryItem
 
 	gzipWriter.Close()
 
-	req, err := http.NewRequest(http.MethodPost, transmitter.endpoint, &postBody)
+	req, err := http.NewRequestWithContext(context.Background(), http.MethodPost, transmitter.endpoint, &postBody)
 	if err != nil {
 		return nil, err
 	}

cli/azd/pkg/llm/github_copilot.go

@@ -385,7 +385,12 @@ func isTokenExpired(expiresAt int64) bool {
 // newCopilotToken gets a Copilot session token using the GitHub token
 func newCopilotToken(githubToken string) (*tokenData, error) {
 	client := &http.Client{}
-	req, err := http.NewRequest("GET", "https://api.github.com/copilot_internal/v2/token", nil)
+	req, err := http.NewRequestWithContext(
+		context.Background(),
+		"GET",
+		"https://api.github.com/copilot_internal/v2/token",
+		nil,
+	)
 	if err != nil {
 		return nil, err
 	}

cli/azd/tools/avmres/main.go

@@ -4,6 +4,7 @@
 package main
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"net/http"
@@ -190,7 +191,7 @@ func fetchGithub(
 	repo string,
 	path string,
 	tag string) ([]byte, error) {
-	req, err := http.NewRequest("GET",
+	req, err := http.NewRequestWithContext(context.Background(), "GET",
 		fmt.Sprintf("https://api.github.com/repos/%s/contents/%s?ref=%s", repo, path, tag), nil)
 	if err != nil {
 		return nil, err