build: fix multiple CVEs by upgrading to go1.26.3

- CVE-2026-42501: cmd/go: malicious module proxy can bypass checksum database
- CVE-2026-39825: net/http/httputil: ReverseProxy forwards queries with more than urlmaxqueryparams parameters
- CVE-2026-39836: net: panic in Dial and LookupPort when handling NUL byte on Windows
- CVE-2026-42499: net/mail: quadratic string concatenation in consumePhrase
- CVE-2026-39820: net/mail: quadratic string concatentation in consumeComment
- CVE-2026-39819: cmd/go: "go bug" follows symlinks in predictable temporary filenames
- CVE-2026-39817: cmd/go: "go tool pack" does not sanitize output paths
- CVE-2026-33814: net/http: infinite loop in HTTP/2 transport when given bad SETTINGS_MAX_FRAME_SIZE
- CVE-2026-39826: html/template: escaper bypass leads to XSS
- CVE-2026-33811: net: crash when handling long CNAME response
- CVE-2026-39823: html/template: bypass of meta content URL escaping causes XSS

.github/workflows/build.yml

@@ -37,7 +37,7 @@ jobs:
         include:
           - job_name: linux
             os: ubuntu-latest
-            go: '~1.26.0'
+            go: '~1.26.3'
             gotags: cmount
             build_flags: '-include "^linux/"'
             check: true
@@ -48,14 +48,14 @@ jobs:
 
           - job_name: linux_386
             os: ubuntu-latest
-            go: '~1.26.0'
+            go: '~1.26.3'
             goarch: 386
             gotags: cmount
             quicktest: true
 
           - job_name: mac_amd64
             os: macos-latest
-            go: '~1.26.0'
+            go: '~1.26.3'
             gotags: 'cmount'
             build_flags: '-include "^darwin/amd64" -cgo'
             quicktest: true
@@ -64,14 +64,14 @@ jobs:
 
           - job_name: mac_arm64
             os: macos-latest
-            go: '~1.26.0'
+            go: '~1.26.3'
             gotags: 'cmount'
             build_flags: '-include "^darwin/arm64" -cgo -macos-arch arm64 -cgo-cflags=-I/usr/local/include -cgo-ldflags=-L/usr/local/lib'
             deploy: true
 
           - job_name: windows
             os: windows-latest
-            go: '~1.26.0'
+            go: '~1.26.3'
             gotags: cmount
             cgo: '0'
             build_flags: '-include "^windows/"'
@@ -81,7 +81,7 @@ jobs:
 
           - job_name: other_os
             os: ubuntu-latest
-            go: '~1.26.0'
+            go: '~1.26.3'
             build_flags: '-exclude "^(windows/|darwin/|linux/)"'
             compile_all: true
             deploy: true
@@ -227,7 +227,7 @@ jobs:
         id: setup-go
         uses: actions/setup-go@v6
         with:
-          go-version: '~1.26.0'
+          go-version: '~1.26.3'
           check-latest: true
           cache: false
           
@@ -318,7 +318,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v6
         with:
-          go-version: '~1.26.0'
+          go-version: '~1.26.3'
 
       - name: Set global environment variables
         run: |